diff --git a/app/controllers/api/v1/accounts/conversations_controller.rb b/app/controllers/api/v1/accounts/conversations_controller.rb
index 59dc051a7..5e7c7d433 100644
--- a/app/controllers/api/v1/accounts/conversations_controller.rb
+++ b/app/controllers/api/v1/accounts/conversations_controller.rb
@@ -69,6 +69,7 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
 
   def update_last_seen
     @conversation.agent_last_seen_at = DateTime.now.utc
+    @conversation.assignee_last_seen_at = DateTime.now.utc if assignee?
     @conversation.save!
   end
 
@@ -136,4 +137,8 @@ class Api::V1::Accounts::ConversationsController < Api::V1::Accounts::BaseContro
   def conversation_finder
     @conversation_finder ||= ConversationFinder.new(current_user, params)
   end
+
+  def assignee?
+    @conversation.assignee_id? && current_user == @conversation.assignee
+  end
 end
diff --git a/app/models/conversation.rb b/app/models/conversation.rb
index 71f6d0a36..bc4db57b6 100644
--- a/app/models/conversation.rb
+++ b/app/models/conversation.rb
@@ -5,6 +5,7 @@
 #  id                    :integer          not null, primary key
 #  additional_attributes :jsonb
 #  agent_last_seen_at    :datetime
+#  assignee_last_seen_at :datetime
 #  contact_last_seen_at  :datetime
 #  custom_attributes     :jsonb
 #  identifier            :string
diff --git a/app/views/api/v1/accounts/conversations/messages/index.json.jbuilder b/app/views/api/v1/accounts/conversations/messages/index.json.jbuilder
index db58b3faa..e1a3e1125 100644
--- a/app/views/api/v1/accounts/conversations/messages/index.json.jbuilder
+++ b/app/views/api/v1/accounts/conversations/messages/index.json.jbuilder
@@ -4,6 +4,7 @@ json.meta do
   json.contact @conversation.contact.push_event_data
   json.assignee @conversation.assignee.push_event_data if @conversation.assignee.present?
   json.agent_last_seen_at @conversation.agent_last_seen_at
+  json.assignee_last_seen_at @conversation.assignee_last_seen_at
 end
 
 json.payload do
diff --git a/app/views/api/v1/conversations/partials/_conversation.json.jbuilder b/app/views/api/v1/conversations/partials/_conversation.json.jbuilder
index 1e35e8217..411cbf8f1 100644
--- a/app/views/api/v1/conversations/partials/_conversation.json.jbuilder
+++ b/app/views/api/v1/conversations/partials/_conversation.json.jbuilder
@@ -31,6 +31,7 @@ json.can_reply conversation.can_reply?
 json.timestamp conversation.last_activity_at.to_i
 json.contact_last_seen_at conversation.contact_last_seen_at.to_i
 json.agent_last_seen_at conversation.agent_last_seen_at.to_i
+json.assignee_last_seen_at conversation.assignee_last_seen_at.to_i
 json.unread_count conversation.unread_incoming_messages.count
 json.additional_attributes conversation.additional_attributes
 json.custom_attributes conversation.custom_attributes
diff --git a/db/migrate/20210922082754_add_assignee_last_seen.rb b/db/migrate/20210922082754_add_assignee_last_seen.rb
new file mode 100644
index 000000000..41ff17818
--- /dev/null
+++ b/db/migrate/20210922082754_add_assignee_last_seen.rb
@@ -0,0 +1,5 @@
+class AddAssigneeLastSeen < ActiveRecord::Migration[6.1]
+  def change
+    add_column :conversations, :assignee_last_seen_at, :datetime
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index dcb1fe612..2b3d5d274 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 2021_09_16_060144) do
+ActiveRecord::Schema.define(version: 2021_09_22_082754) do
 
   # These are extensions that must be enabled in order to support this database
   enable_extension "pg_stat_statements"
@@ -296,6 +296,7 @@ ActiveRecord::Schema.define(version: 2021_09_16_060144) do
     t.bigint "campaign_id"
     t.datetime "snoozed_until"
     t.jsonb "custom_attributes", default: {}
+    t.datetime "assignee_last_seen_at"
     t.index ["account_id", "display_id"], name: "index_conversations_on_account_id_and_display_id", unique: true
     t.index ["account_id"], name: "index_conversations_on_account_id"
     t.index ["assignee_id", "account_id"], name: "index_conversations_on_assignee_id_and_account_id"
diff --git a/spec/controllers/api/v1/accounts/conversations_controller_spec.rb b/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
index ec53ec853..fdb8e51d5 100644
--- a/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
+++ b/spec/controllers/api/v1/accounts/conversations_controller_spec.rb
@@ -393,6 +393,19 @@ RSpec.describe 'Conversations API', type: :request do
         expect(response).to have_http_status(:success)
         expect(conversation.reload.agent_last_seen_at).not_to eq nil
       end
+
+      it 'updates assignee last seen' do
+        conversation.update!(assignee_id: agent.id)
+
+        expect(conversation.reload.assignee_last_seen_at).to eq nil
+
+        post "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}/update_last_seen",
+             headers: agent.create_new_auth_token,
+             as: :json
+
+        expect(response).to have_http_status(:success)
+        expect(conversation.reload.assignee_last_seen_at).not_to eq nil
+      end
     end
   end