Upper extremity (UE) dysfunction resulting from stroke significantly affects a person's ability to complete self-care activities, consequently diminishing functional independence. Effective interventions that improve UE function in persons with stroke are needed. To explore the effectiveness of the Bimanual Arm Trainer (BAT) compared with traditional occupational therapy treatment sessions (i.e., a control group) on improving UE function after acute ischemic stroke. Clinical trial, two-group, nonrandomized repeated-measures design. Inpatient rehabilitation facility. Twenty-seven persons with ischemic stroke and an Action Research Arm Test (ARAT) score ≤17. Minimum of three 10-min sessions on the BAT. ARAT, Upper Extremity Fugl-Meyer Assessment of Motor Recovery after Stroke (FMA-UE). Both the intervention and control groups showed significant improvement on the ARAT from evaluation to discharge (main effect of time: p = .02). There was no statistically significant main effect of group and no significant Time × Group interaction (p = .63). FMA-UE scores also improved significantly in the intervention group from evaluation to discharge (p < .001). FMA-UE scores were not available for the control group. Both the intervention and control groups demonstrated significant improvements in UE function from evaluation to discharge. There were no statistically significant differences between groups, indicating that the BAT results in similar improvements in UE function, as would be expected in traditional occupational therapy. Further research is warranted to examine additional BAT programs, use different outcome measures, and assess participants over a longer time span. Plain-Language Summary: The Bimanual Arm Trainer (BAT) is a novel device that can be used in occupational therapy to improve arm function among stroke patients. There is limited research on BAT's effectiveness in improving arm function among stroke patients. In an acute inpatient rehabilitation setting, we compared outcome scores of patients who received traditional occupational therapy services with those who also used the BAT. Both groups achieved significant improvements in arm function from evaluation to discharge. We found that the addition of the BAT interventions did not significantly affect the outcome measure scores for either group. We conclude that more research is needed to examine additional BAT programs, use different outcome measures, and assess participants over a longer period of time.