BACKGROUND: Lipomas are benign soft tissue tumours, progressively expanding in volume. Beside frequent aesthetic consequences, lipomas can also exert pressure on surrounding tissues and structures. MATERIALS AND METHODS: A case of a subpectoral infraclavicular lipoma compressing the axillo-subclavicular neurovascular bundle, produced unilateral brachialgia, thereby simulating a Thoracic Outlet Syndrome. The expansive, but non-infiltrative, nature of the lipoma allowed local excision in the vicinity of the brachial plexus and infraclavicular vascular structures. RESULTS: Surgical removal of the lipoma resulted in complete remission of symptoms in the left arm and hand. CONCLUSIONS: In the presence of unilateral brachialgia, a subpectoral tumour causing a Thoracic Outlet Syndrome should always be excluded in the absence of other relevant pathology.