Objective: Effort allocation is a multi-faceted process driving both the decision to choose a high effort–high reward alternative over a low effort–low reward alternative, and the execution of this decision by recruiting sufficient effort. The objectives of our study were to examine whether children with ADHD would (a) show different reward–effort cost trade-off, and (b) have difficulty executing their decision. Method: 50 children, aged 9 to 15, with and without ADHD, had to choose between high effort–high reward and low effort–low reward alternatives using a handheld dynamometer and to execute their choice. Results: Children with ADHD and controls made similar number of high-effort choices (p = .806). However, children with ADHD executed their high-effort choices less frequently compared with controls (p = .029). Conclusion: These findings suggest that children with ADHD are not characterized by different effort–reward trade-off but rather by difficulties in recruiting effort for their preferences implementation.