diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index f02771b467ff8..d42e5f30398e2 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   bin/setup uses `bun` instead of `yarn` when generated an app with bun
+
+    Use `bun install` on `bin/setup` when using `bun`.
+
+    *Cadu Ribeiro*
+
 *   `config/application.rb` now includes
 
     ```ruby
diff --git a/railties/lib/rails/generators/app_base.rb b/railties/lib/rails/generators/app_base.rb
index c5a8dc28250ac..68356da0da1da 100644
--- a/railties/lib/rails/generators/app_base.rb
+++ b/railties/lib/rails/generators/app_base.rb
@@ -467,10 +467,16 @@ def hotwire_gemfile_entry
       end
 
       def using_node?
+        return if using_bun?
+
         (options[:javascript] && !%w[importmap].include?(options[:javascript])) ||
           (options[:css] && !%w[tailwind sass].include?(options[:css]))
       end
 
+      def using_bun?
+        options[:javascript] == "bun"
+      end
+
       def node_version
         if using_node?
           ENV.fetch("NODE_VERSION") do
@@ -569,12 +575,12 @@ def dockerfile_deploy_packages
       def css_gemfile_entry
         return unless options[:css]
 
-        if !using_node? && options[:css] == "tailwind"
+        if using_node? || using_bun?
+          GemfileEntry.floats "cssbundling-rails", "Bundle and process CSS [https://github.com/rails/cssbundling-rails]"
+        elsif options[:css] == "tailwind"
           GemfileEntry.floats "tailwindcss-rails", "Use Tailwind CSS [https://github.com/rails/tailwindcss-rails]"
-        elsif !using_node? && options[:css] == "sass"
+        elsif options[:css] == "sass"
           GemfileEntry.floats "dartsass-rails", "Use Dart SASS [https://github.com/rails/dartsass-rails]"
-        else
-          GemfileEntry.floats "cssbundling-rails", "Bundle and process CSS [https://github.com/rails/cssbundling-rails]"
         end
       end
 
@@ -684,12 +690,12 @@ def run_hotwire
       def run_css
         return if !options[:css] || !bundle_install?
 
-        if !using_node? && options[:css] == "tailwind"
+        if using_bun? || using_node?
+          rails_command "css:install:#{options[:css]}"
+        elsif options[:css] == "tailwind"
           rails_command "tailwindcss:install"
-        elsif !using_node? && options[:css] == "sass"
+        elsif options[:css] == "sass"
           rails_command "dartsass:install"
-        else
-          rails_command "css:install:#{options[:css]}"
         end
       end
 
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/setup.tt b/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
index 1cf6fe38a6b5c..3625f9c94ac2d 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
+++ b/railties/lib/rails/generators/rails/app/templates/bin/setup.tt
@@ -19,6 +19,10 @@ FileUtils.chdir APP_ROOT do
 
   # Install JavaScript dependencies
   system("yarn check --check-files") || system!("yarn install")
+<% elsif using_bun? %>
+  # Install JavaScript dependencies
+
+  system("bun install")
 <% end -%>
 <% unless options.skip_active_record? -%>