This analysis aimed to assess the relationship between race and clinical response to long-acting, injectable risperidone treatment in patients with schizophrenia or schizoaffective disorder. In a 12-week, randomized, double-blind study, patients with schizophrenia or schizoaffective disorder received placebo or long-acting risperidone (25, 50 or 75 mg every 2 weeks). Data were stratified by race as identified by demographic information: Caucasian, African-American or Other. Psychotic symptoms were assessed by the Positive and Negative Syndrome Scale (PANSS); movement disorders by the Extrapyramidal Symptom Rating Scale (ESRS); adverse events (AEs) were reported spontaneously. Data were available for 439 patients: 193 Caucasian (44%), 174 (40%) African-American and 72 (16%) Other patients. Baseline characteristics were similar between racial groups, as were study completion rates (overall: 30% placebo; 48% long-acting risperidone). There was a significant effect of treatment (P<0.001), but not of race, on improvement in PANSS total scores from baseline to endpoint. ESRS scores were low throughout the study, and no significant impact of race was observed. Overall rates of AEs were similar among the racial groups. Race did not appear to impact the efficacy and tolerability of long-acting risperidone.