Lipomas are the commonest benign tumour, made up exclusively of adipose tissue, and can arise anywhere in the body. However, giant lipomas of the hand, defined as >5 cm in diameter, are rare. They have the potential to invade into surrounding areas and cause a multitude of symptoms due to the compression and proximity of underlying structures. We describe a case of a 64-year-old woman who presents with a swelling of the left thenar eminence, associated with numbness and tingling in all fingers. Magnetic resonance imaging and nerve conduction studies confirmed the diagnosis of a lipoma causing median nerve compression. The patient underwent elective surgical excision with good postoperative recovery. The excised lesion, measuring 12 × 7 × 2.4 cm, is one of the largest giant lipomas of the hand reported in literature, and the first to demonstrate invasion from the mid palmar space into both the dorsal sub-aponeurotic space and carpal tunnel.