This study aimed to evaluate the anatomic and functional outcome of retrograde intramedullary single wire fixation for metacarpal shaft fractures of the little finger. Forty consecutive patients with closed metacarpal shaft fractures of the little finger who have been treated with retrograde intramedullary single wire fixation were evaluated. Fracture union and angulation were analyzed radiologically, and clinical evaluations were performed including the percentage of total active motion (%TAM), disabilities of the arm, shoulder and hand (DASH) score, and complications. Fracture union was achieved in all cases, and callus formation was obvious at 42 days postoperatively. The average angulation of the fracture site was 2.7° in the coronal plane and 1.0° in the sagittal plane at the last follow-up, and no measurable metacarpal shortening was observed. Mean %TAM was 92.0 ± 6.2% (range, 84.6-100%), and DASH score was 2.8 ± 1.2 (range, 0-6). There were two cases of pin migration as intermediate complications. A closed reduction with subsequent percutaneous retrograde K-wire fixation produced good radiological and functional results. We recommend this minimally invasive technique which provides adequate fixation of displaced little finger metacarpal shaft fractures with good functional results and low morbidity.