diff --git a/app/components/attachment/gallery_item_component.rb b/app/components/attachment/gallery_item_component.rb
index 748387cf4..0aa3e766f 100644
--- a/app/components/attachment/gallery_item_component.rb
+++ b/app/components/attachment/gallery_item_component.rb
@@ -17,7 +17,13 @@ class Attachment::GalleryItemComponent < ApplicationComponent
   def gallery_demande? = @gallery_demande
 
   def libelle
-    from_dossier? ? attachment.record.libelle : 'Pièce jointe au message'
+    if from_dossier?
+      attachment.record.libelle
+    elsif from_messagerie?
+      'Pièce jointe au message'
+    elsif from_avis_externe?
+      'Pièce jointe à l’avis'
+    end
   end
 
   def origin
@@ -28,6 +34,10 @@ class Attachment::GalleryItemComponent < ApplicationComponent
       'Messagerie (instructeur)'
     when from_messagerie_usager?
       'Messagerie (usager)'
+    when from_avis_externe_instructeur?
+      'Avis externe (instructeur)'
+    when from_avis_externe_expert?
+      'Avis externe (expert)'
     end
   end
 
@@ -83,4 +93,16 @@ class Attachment::GalleryItemComponent < ApplicationComponent
   def from_messagerie_usager?
     from_messagerie? && attachment.record.instructeur.nil?
   end
+
+  def from_avis_externe?
+    attachment.record.is_a?(Avis)
+  end
+
+  def from_avis_externe_instructeur?
+    from_avis_externe? && attachment.name == 'introduction_file'
+  end
+
+  def from_avis_externe_expert?
+    from_avis_externe? && attachment.name == 'piece_justificative_file'
+  end
 end
diff --git a/app/controllers/instructeurs/dossiers_controller.rb b/app/controllers/instructeurs/dossiers_controller.rb
index a5ac2c0db..58e911b29 100644
--- a/app/controllers/instructeurs/dossiers_controller.rb
+++ b/app/controllers/instructeurs/dossiers_controller.rb
@@ -513,11 +513,16 @@ module Instructeurs
           .commentaires
           .includes(piece_jointe_attachments: :blob)
           .map(&:piece_jointe)
-          .map(&:attachments)
-          .flatten
+          .flat_map(&:attachments)
           .map(&:id)
 
-        champs_attachments_ids + commentaires_attachments_ids
+        avis_attachments_ids = dossier
+          .avis.flat_map { [_1.introduction_file, _1.piece_justificative_file] }
+          .flat_map(&:attachments)
+          .compact
+          .map(&:id)
+
+        champs_attachments_ids + commentaires_attachments_ids + avis_attachments_ids
       end
       @gallery_attachments = ActiveStorage::Attachment.where(id: gallery_attachments_ids)
     end
diff --git a/app/models/concerns/blob_image_processor_concern.rb b/app/models/concerns/blob_image_processor_concern.rb
index 08d6f1067..f42abeee8 100644
--- a/app/models/concerns/blob_image_processor_concern.rb
+++ b/app/models/concerns/blob_image_processor_concern.rb
@@ -10,7 +10,7 @@ module BlobImageProcessorConcern
   end
 
   def representation_required?
-    from_champ? || from_messagerie? || logo? || from_action_text?
+    from_champ? || from_messagerie? || logo? || from_action_text? || from_avis?
   end
 
   private
@@ -31,6 +31,10 @@ module BlobImageProcessorConcern
     attachments.any? { _1.record.class == ActionText::RichText }
   end
 
+  def from_avis?
+    attachments.any? { _1.record.class == Avis }
+  end
+
   def watermark_required?
     attachments.any? { _1.record.class == Champs::TitreIdentiteChamp }
   end
diff --git a/spec/components/attachment/gallery_item_component_spec.rb b/spec/components/attachment/gallery_item_component_spec.rb
index 382c6cf10..172ed0574 100644
--- a/spec/components/attachment/gallery_item_component_spec.rb
+++ b/spec/components/attachment/gallery_item_component_spec.rb
@@ -101,4 +101,52 @@ RSpec.describe Attachment::GalleryItemComponent, type: :component do
       end
     end
   end
+
+  context "when attachment is from an avis" do
+    context 'from an instructeur' do
+      let(:avis) { create(:avis, :with_introduction, dossier: dossier) }
+      let(:attachment) { avis.introduction_file.attachment }
+
+      it "displays a generic libelle, link, tag and renders title" do
+        expect(subject).to have_text('Pièce jointe à l’avis')
+        expect(subject).to have_link(filename)
+        expect(subject).to have_text('Avis externe (instructeur)')
+        expect(component.title).to eq("Pièce jointe à l’avis -- #{filename}")
+      end
+
+      context "when instructeur has not seen it yet" do
+        let(:seen_at) { now - 1.day }
+
+        before do
+          attachment.blob.update(created_at: now)
+        end
+
+        it 'displays datetime in the right style' do
+          expect(subject).to have_css('.highlighted')
+        end
+      end
+
+      context "when instructeur has already seen it" do
+        let!(:seen_at) { now }
+
+        before do
+          freeze_time
+          attachment.blob.touch(:created_at)
+        end
+
+        it 'displays datetime in the right style' do
+          expect(subject).not_to have_css('.highlighted')
+        end
+      end
+    end
+
+    context 'from an expert' do
+      let(:avis) { create(:avis, :with_piece_justificative, dossier: dossier) }
+      let(:attachment) { avis.piece_justificative_file.attachment }
+
+      it "displays the right tag" do
+        expect(subject).to have_text('Avis externe (expert)')
+      end
+    end
+  end
 end
diff --git a/spec/controllers/instructeurs/dossiers_controller_spec.rb b/spec/controllers/instructeurs/dossiers_controller_spec.rb
index 3ec50f3cc..94edad04e 100644
--- a/spec/controllers/instructeurs/dossiers_controller_spec.rb
+++ b/spec/controllers/instructeurs/dossiers_controller_spec.rb
@@ -1486,6 +1486,9 @@ describe Instructeurs::DossiersController, type: :controller do
     let(:logo_path) { 'spec/fixtures/files/logo_test_procedure.png' }
     let(:rib_path) { 'spec/fixtures/files/RIB.pdf' }
     let(:commentaire) { create(:commentaire, dossier: dossier) }
+    let(:expert) { create(:expert) }
+    let(:experts_procedure) { create(:experts_procedure, expert: expert, procedure: procedure) }
+    let(:avis) { create(:avis, :with_answer, :with_piece_justificative, dossier: dossier, claimant: expert, experts_procedure: experts_procedure) }
 
     before do
       dossier.champs.first.piece_justificative_file.attach(
@@ -1502,20 +1505,29 @@ describe Instructeurs::DossiersController, type: :controller do
         metadata: { virus_scan_result: ActiveStorage::VirusScanner::SAFE }
       )
 
+      avis.piece_justificative_file.attach(
+        io: File.open(rib_path),
+        filename: "RIB.pdf",
+        content_type: "application/pdf",
+        metadata: { virus_scan_result: ActiveStorage::VirusScanner::SAFE }
+      )
+
       get :pieces_jointes, params: {
         procedure_id: procedure.id,
         dossier_id: dossier.id
       }
     end
 
-    it 'returns pieces jointes from champs and from messagerie' do
+    it 'returns pieces jointes from champs, messagerie and avis' do
       expect(response.body).to include('Télécharger le fichier toto.txt')
       expect(response.body).to include('Télécharger le fichier logo_test_procedure.png')
       expect(response.body).to include('Télécharger le fichier RIB.pdf')
       expect(response.body).to include('Visualiser')
-      expect(assigns(:gallery_attachments).count).to eq 3
+      expect(response.body).to include('Pièce jointe au message')
+      expect(response.body).to include('Pièce jointe à l’avis')
+      expect(assigns(:gallery_attachments).count).to eq 4
       expect(assigns(:gallery_attachments)).to all(be_a(ActiveStorage::Attachment))
-      expect([Champs::PieceJustificativeChamp, Champs::TitreIdentiteChamp, Commentaire]).to include(*assigns(:gallery_attachments).map { _1.record.class })
+      expect([Champs::PieceJustificativeChamp, Champs::TitreIdentiteChamp, Commentaire, Avis]).to include(*assigns(:gallery_attachments).map { _1.record.class })
     end
   end