diff --git a/app/models/ci/pipeline_variable.rb b/app/models/ci/pipeline_variable.rb
index 017ec0b145a8bb0122f8f4dc2a642f331b097f41..08514d6af4e9ab1c7650674850cb82c56b64ea72 100644
--- a/app/models/ci/pipeline_variable.rb
+++ b/app/models/ci/pipeline_variable.rb
@@ -10,5 +10,9 @@ module Ci
     alias_attribute :secret_value, :value
 
     validates :key, uniqueness: { scope: :pipeline_id }
+
+    def hook_attrs
+      { key: key, value: value }
+    end
   end
 end
diff --git a/changelogs/unreleased/pipeline-event-variables.yml b/changelogs/unreleased/pipeline-event-variables.yml
new file mode 100644
index 0000000000000000000000000000000000000000..90fd964efd59ec21bc1e6bbf457f5427ab4ee4fa
--- /dev/null
+++ b/changelogs/unreleased/pipeline-event-variables.yml
@@ -0,0 +1,5 @@
+---
+title: pipeline webhook event now contain pipeline variables
+merge_request: 18171
+author: Pierre Tardy
+type: added
diff --git a/doc/user/project/integrations/webhooks.md b/doc/user/project/integrations/webhooks.md
index 5a38f5d8aed513bce4f13e6b9e991d49f908d784..7d12cd8f7c2da9f8dcd1279473197822b8a3bd1e 100644
--- a/doc/user/project/integrations/webhooks.md
+++ b/doc/user/project/integrations/webhooks.md
@@ -943,7 +943,13 @@ X-Gitlab-Event: Pipeline Hook
       ],
       "created_at": "2016-08-12 15:23:28 UTC",
       "finished_at": "2016-08-12 15:26:29 UTC",
-      "duration": 63
+      "duration": 63,
+      "variables": [
+        {
+          "key": "NESTOR_PROD_ENVIRONMENT",
+          "value": "us-west-1"
+        }
+      ]
    },
    "user":{
       "name": "Administrator",
diff --git a/lib/gitlab/data_builder/pipeline.rb b/lib/gitlab/data_builder/pipeline.rb
index eb246d393a1e4e99ad1ee432f8a36625b0b056fb..f382992cb0a5ccda245ab7495b2e6e1a452af5d8 100644
--- a/lib/gitlab/data_builder/pipeline.rb
+++ b/lib/gitlab/data_builder/pipeline.rb
@@ -26,7 +26,8 @@ module Gitlab
           stages: pipeline.stages_names,
           created_at: pipeline.created_at,
           finished_at: pipeline.finished_at,
-          duration: pipeline.duration
+          duration: pipeline.duration,
+          variables: pipeline.variables.map(&:hook_attrs)
         }
       end
 
diff --git a/spec/lib/gitlab/data_builder/pipeline_spec.rb b/spec/lib/gitlab/data_builder/pipeline_spec.rb
index 9ca960502c8e6b454a5dd1feb8627cb16502f26b..98f1696badb31bcb126f1b030ba72bdf8c4d40ed 100644
--- a/spec/lib/gitlab/data_builder/pipeline_spec.rb
+++ b/spec/lib/gitlab/data_builder/pipeline_spec.rb
@@ -6,10 +6,10 @@ describe Gitlab::DataBuilder::Pipeline do
 
   let(:pipeline) do
     create(:ci_pipeline,
-           project: project,
-           status: 'success',
-           sha: project.commit.sha,
-           ref: project.default_branch)
+          project: project,
+          status: 'success',
+          sha: project.commit.sha,
+          ref: project.default_branch)
   end
 
   let!(:build) { create(:ci_build, pipeline: pipeline) }
@@ -20,18 +20,35 @@ describe Gitlab::DataBuilder::Pipeline do
     let(:build_data) { data[:builds].first }
     let(:project_data) { data[:project] }
 
-    it { expect(attributes).to be_a(Hash) }
-    it { expect(attributes[:ref]).to eq(pipeline.ref) }
-    it { expect(attributes[:sha]).to eq(pipeline.sha) }
-    it { expect(attributes[:tag]).to eq(pipeline.tag) }
-    it { expect(attributes[:id]).to eq(pipeline.id) }
-    it { expect(attributes[:status]).to eq(pipeline.status) }
-    it { expect(attributes[:detailed_status]).to eq('passed') }
+    it 'has correct attributes' do
+      expect(attributes).to be_a(Hash)
+      expect(attributes[:ref]).to eq(pipeline.ref)
+      expect(attributes[:sha]).to eq(pipeline.sha)
+      expect(attributes[:tag]).to eq(pipeline.tag)
+      expect(attributes[:id]).to eq(pipeline.id)
+      expect(attributes[:status]).to eq(pipeline.status)
+      expect(attributes[:detailed_status]).to eq('passed')
+      expect(build_data).to be_a(Hash)
+      expect(build_data[:id]).to eq(build.id)
+      expect(build_data[:status]).to eq(build.status)
+      expect(project_data).to eq(project.hook_attrs(backward: false))
+    end
 
-    it { expect(build_data).to be_a(Hash) }
-    it { expect(build_data[:id]).to eq(build.id) }
-    it { expect(build_data[:status]).to eq(build.status) }
+    context 'pipeline without variables' do
+      it 'has empty variables hash' do
+        expect(attributes[:variables]).to be_a(Array)
+        expect(attributes[:variables]).to be_empty()
+      end
+    end
 
-    it { expect(project_data).to eq(project.hook_attrs(backward: false)) }
+    context 'pipeline with variables' do
+      let(:build) { create(:ci_build, pipeline: pipeline) }
+      let(:data) { described_class.build(pipeline) }
+      let(:attributes) { data[:object_attributes] }
+      let!(:pipeline_variable) { create(:ci_pipeline_variable, pipeline: pipeline, key: 'TRIGGER_KEY_1', value: 'TRIGGER_VALUE_1') }
+
+      it { expect(attributes[:variables]).to be_a(Array) }
+      it { expect(attributes[:variables]).to contain_exactly({ key: 'TRIGGER_KEY_1', value: 'TRIGGER_VALUE_1' }) }
+    end
   end
 end
diff --git a/spec/models/ci/pipeline_variable_spec.rb b/spec/models/ci/pipeline_variable_spec.rb
index 889c243c8d8fda86aebba3be4cab9f9c3acda705..03d09cb31d61f9ba01a577dda75b50b0fee409cc 100644
--- a/spec/models/ci/pipeline_variable_spec.rb
+++ b/spec/models/ci/pipeline_variable_spec.rb
@@ -5,4 +5,13 @@ describe Ci::PipelineVariable do
 
   it { is_expected.to include_module(HasVariable) }
   it { is_expected.to validate_uniqueness_of(:key).scoped_to(:pipeline_id) }
+
+  describe '#hook_attrs' do
+    let(:variable) { create(:ci_pipeline_variable, key: 'foo', value: 'bar') }
+
+    subject { variable.hook_attrs }
+
+    it { is_expected.to be_a(Hash) }
+    it { is_expected.to eq({ key: 'foo', value: 'bar' }) }
+  end
 end