Subacute osteomyelitis is a rare affection. Clinical presentation is often unclear and can lead to a delay in diagnosis. As a matter of fact, subactue metacarpal osteomyelitis is usually missed at the first time, so that some complications may occur like brachymetacarpia or loss of motion. We report a 10 year-old boy, with a subacute metaphyseal osteomyelitis of the second right metacarpal bone. The radiological features can mimic various benign or malignant bone tumours and non-pyogenic infections. Histological confirmation is necessary to avoid a delay in diagnosis. Treatment was based on antibiotics and surgical debridement. No infectious agent was found in bacteriological exams. At 1 year of follow-up, noncompliance was reported with a normal motion of the finger. X-ray views showed a bone reconstruction with a fibrosis of ulnar part of the metaphysis without length discrepancy.