Fibrolipomatous hamartoma is a rare benign neoplasm that in some cases is associated with macrodactylia. We describe a 31-year-old man who had a tissue enlargement in the wrist, second and third fingers of the left hand since infancy. At 23-years-old he began with continuous, progressive and high intensity pain that occurred more frequently at night, localized in the left hand. It was associated with paraesthesias and hypostesias predominantly at the fingers described above. Investigation with X-ray, ultrasonography, electrodiagnosis, magnetic resonance image of the left wrist and hand showed carpal tunnel syndrome with macrodactylia by fibrolipomatous hamartoma of the median nerve. The patient did not a have good response to clinical therapy, so he was submitted to a surgical decompression of the left carpal tunnel, and after three months of follow up is asymptomatic.