[Purpose] This study examined how an ankle-foot orthosis (AFO) influences the weight-bearing of chronic stroke patients during the performance of five functional standing tasks. [Subjects and Methods] Sixteen patients with stroke participated in this experiment. The subjects performed functional standing tasks with or without the AFO and weight bearing was measured during the tasks. [Results] Patients showed increased weight-bearing ability on the affected side during wearing the AFO in all tasks, and there were significant differences among Tasks 1, 2, and 3. Patients showed a small amount of increased weight bearing on the unaffected side while wearing the AFO in all tasks except for Task 2. [Conclusion] ADL-related functional standing tasks with AFO increased the weight bearing.