Objective: To evaluate the immediate and retention effects of a 4-week training program on the performance of locomotor-related tasks in chronic stroke. Design: Randomized, controlled pilot study with 2-month follow-up. Setting: Rehabilitation center. Subjects: A convenience sample consisting of 12 chronic stroke subjects was used. Subjects were randomly assigned to the experimental or the control group. Three subjects withdrew from the study. Intervention: Both experimental and control groups participated in exercise classes three times a week for 4 weeks. The exercise class for the experimental group focused on strengthening the affected lower limb and practicing functional tasks involving the lower limbs, while the control group practiced upper-limb tasks. Main Outcome Measures: Lower-limb function was evaluated by measuring walking speed and endurance, peak vertical ground reaction force through the affected foot during sit-to-stand, and the step test. Results: The experimental group demonstrated significant immediate and retained (2-month follow-up) improvement (p ≤ .05) compared with the control group in walking speed and endurance, force production through the affected leg during sit-to-stand, and the number of repetitions of the step test. Conclusion: The pilot study provides evidence for the efficacy of a task- related circuit class at improving locomotor function in chronic stroke. (C) 2000 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.