OBJECTIVE. Wrist buckle fractures are a frequent reason for emergency department visits. Although textbooks recommend 2 to 4 weeks of immobilization in a short arm cast, management varies. Treatment with both casts and splints is common, and length of immobilization varies. The objective was to determine if children with distal radius and/or ulna buckle fractures treated with a removable splint have better physical functioning than those treated with a short arm cast for 3 weeks. METHODS. This was a randomized, controlled trial in the emergency department of an academic, tertiary care children's hospital. Participants were children 6 to 15 years of age with distal radius and/or ulna buckle fractures who were randomly assigned to treatment with a short arm cast for 3 weeks or a removable splint. Cast removal was at 3 weeks. A validated self-reported outcome tool, the Activities Scales for Kids performance version (ASKp), was used to measure physical functioning over a 4-week period. The main outcome was the ASKp score at 14 days postinjury. RESULTS. We randomly assigned 113 patients, and 87 were included in the final analysis: 42 in the splint group and 45 in the cast group. Study groups were similar in age, gender, bone fractured, and dominant hand injured. There were significant differences in ASKp score at day 14 and change in ASKp from baseline at days 14 and 20, indicating better functioning in the splint group. Splinted children had less difficulty with bathing throughout the entire study. There were no significant differences in pain between groups as measured by visual analog scale. There were no refractures. CONCLUSIONS. Children treated with removable splinting have better physical functioning and less difficulty with activities than those treated with a cast.