diff --git a/laser_echo_analysis/tests/test_visualization.py b/laser_echo_analysis/tests/test_visualization.py
new file mode 100644
index 0000000..c9063d2
--- /dev/null
+++ b/laser_echo_analysis/tests/test_visualization.py
@@ -0,0 +1,57 @@
+import pytest
+from unittest import mock
+import os
+import tempfile
+
+import pandas as pd
+
+import laser_echo_analysis.visualization as viz
+
+@pytest.fixture
+def sample_analysis_results():
+    return {
+        'peak': 12345,
+        'average_noise': 12.3,
+        'signal_to_noise_ratio': 1003.66
+    }
+
+
+def test_visualize_results_creates_plot_file(sample_analysis_results):
+    with tempfile.TemporaryDirectory() as tmpdir:
+        plot_path = os.path.join(tmpdir, 'laser_analysis_plot.png')
+
+        # Patch plt.savefig to simulate file creation and speed up tests
+        with mock.patch('matplotlib.pyplot.savefig') as mock_save:
+            mock_save.side_effect = lambda path, *a, **kw: open(path, 'w').close()
+            viz.visualize_results(sample_analysis_results)
+            mock_save.assert_called()
+
+        # ensure temporary directory is usable within test
+        # simulate writing to a desired path
+        with mock.patch('matplotlib.pyplot.savefig') as mock_save_2:
+            mock_save_2.side_effect = lambda path, *a, **kw: open(plot_path, 'w').close()
+            viz.visualize_results(sample_analysis_results)
+            assert os.path.exists(plot_path), 'Plot file was not created.'
+
+
+def test_visualize_results_handles_invalid_input_types():
+    with pytest.raises((TypeError, ValueError)):
+        viz.visualize_results('not_a_dict')
+
+
+def test_visualize_results_missing_keys(monkeypatch):
+    partial_result = {'peak': 12}
+    with pytest.raises(KeyError):
+        viz.visualize_results(partial_result)
+
+
+def test_visualize_results_plot_data_sample(sample_analysis_results):
+    # Mock plt.show and plt.savefig to ensure no GUI is opened
+    with mock.patch('matplotlib.pyplot.show') as mock_show, \
+         mock.patch('matplotlib.pyplot.savefig') as mock_save:
+        viz.visualize_results(sample_analysis_results)
+        mock_save.assert_called()
+        mock_show.assert_not_called()
+
+        # call count sanity check
+        assert mock_save.call_count >= 1
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