Racial disparities in the process and outcome of health care may be partially explained by differences in time use during outpatient visits by African-American and white patients. This study was undertaken to determine whether physicians use their time in clinical encounters with African-American patients differently than with white patients. This study was a multimethod, cross-sectional study conducted between October 1994 and August 1995 in 84 family practices in northeast Ohio. Participants were 4,352 white and African-American outpatients visiting 138 physicians. Time use during the patient visit was measured by the Davis Observation Code, which categorizes every 20-second interval into 20 different behavioral categories. Among 3,743 white and 509 African-American patients, after adjustment for potential confounders, visits by African-American patients were slightly longer than visits with white patients (10.7 vs. 10.1 minutes, p = 0.027). After further adjustment for multiple comparisons, physicians spent a lower proportion of time intervals with African-American patients as compared to white patients planning treatment (29.0% vs. 32.1%, p < 0.001), providing health education (16.4% vs. 19.7%, p < 0.001), chatting (5.2% vs. 7.6%, p < 0.001), assessing patients' health knowledge (0.8% vs. 1.2%, p < 0.001), and answering questions (5.8% vs. 6.9%, p = 0.002). Physicians spent relatively more time intervals with African-American patients discussing what is to be accomplished (9.3% vs. 7.6%, p < 0.001) and providing substance use assessment and advice (0.8% vs. 0.4%, p = 0.001). In conclusion, physicians spend time differently with African-American as compared with white patients. These differences may represent appropriate tailoring of services to meet unique needs, but could also represent racial bias.