Background: Finger metacarpal fractures represent up to 31% of all hand fractures, and most can be treated nonoperatively. Whether operative treatment is superior to nonoperative treatment for oblique and/or spiral finger metacarpal shaft fractures (MSFs) is unknown.Methods: Forty-two patients with displaced oblique and/or spiral finger MSFs were randomized to either nonoperative treatment with unrestricted mobilization or operative treatment with screw fixation. The primary outcome was grip strength in the injured hand compared with the uninjured hand at the 1-year follow-up. Secondary outcomes were the Disabilities of the Arm, Shoulder and Hand score, range of motion, metacarpal shortening, complications, sick leave duration, patient satisfaction, and costs.Results: All patients attended the 1-year follow-up. Mean grip strength relative to that in the contralateral hand was 104% (95% confidence interval [CI], 89% to 120%) in the nonoperative group and 96% (95% CI, 89% to 103%) in the operative group (p = 0.34). Mean metacarpal shortening was 5.3 mm (95% CI, 4.2 to 6.4 mm) in the nonoperative group and 2.3 mm (95% CI, 0.8 to 3.9 mm) in the operative group. In the nonoperative group, 1 minor complication was observed; in the operative group, there were 4 minor complications and 3 reoperations. The costs were estimated at 1,347 U.S. dollars (USD) for nonoperative treatment compared with 3,834 USD for operative treatment. Sick leave duration was significantly shorter in the nonoperative group (12 days [95% CI, 5 to 21 days] versus 35 days [95% CI, 20 to 54 days]) (p = 0.008).Conclusions: When treated with unrestricted mobilization, patients with a single displaced spiral and/or oblique finger MSF have outcomes comparable to those treated operatively, despite metacarpal shortening. Costs are substantially higher (2.8 times) and sick leave is significantly higher in the operative group.