Objectives: To analyze responsiveness to change of 2 outcome measures in the lateropulsion population after stroke. Lateropulsion describes an atypical balance problem after stroke where patients actively push themselves toward their paretic side. Secondary aims were to measure the incidence of lateropulsion and evaluate the site of the brain most commonly involved in lateropulsion. Design: Stroke patients were screened for lateropulsion on admission to rehabilitation. Those demonstrating lateropulsion were assessed every 2 weeks using 2 scales to measure progress. Analysis of variance and the standardized response mean (SRM) were used to analyze change for each scale. Setting: Rehabilitation and geriatric units. Participants: Prospective purposive sample of stroke patients (N=43) demonstrating lateropulsion on admission from a consecutive admission sample of 160. To allow comparison, data from 43 stroke patients who did not display lateropulsion were collected retrospectively, matched on age (±5y) and sex. Interventions: Not applicable. Main Outcome Measures: Incidence of lateropulsion was calculated as a percentage of stroke patients admitted. Responsiveness to change was measured by using the Burke Lateropulsion Scale (BLS), to quantify severity of lateropulsion, and the Postural Assessment Scale for Stroke (PASS), which measures postural abilities. Results: Of 160 stroke patients, 26.9% displayed lateropulsion (mean age, 72y; 51% men). The BLS and PASS had high levels of measurement responsiveness (BLS SRM =1.48 and 2.24; PASS SRM =1.76 and 1.87) at 4 and 8 weeks, respectively. Conclusions: The BLS and PASS are responsive scales to monitor progress and recovery during rehabilitation. As more than 25% of stroke patients admitted to rehabilitation may exhibit lateropulsion, these 2 scales could be valuable in monitoring progress and designing future intervention studies.