A telephone survey of 120 randomly selected primary care physicians in New York City was completed in October, 1984 (response rate = 90%) concerning physicians' recommendations for health promotion and disease prevention. Responses from physicians with 50% or more Black and Hispanic patients were compared with responses from physicians with 50% or more White patients. The former were found to be less likely to follow guidelines from nationally recognized organizations for health promotion and disease prevention, although they were just as likely to value the importance of prevention in primary care. For example, physicians with predominantly Black and Hispanic patient populations were significantly less likely to recommend screening mammography (7% versus 23%) or recommend influenza vaccination for patients 65 or older (48% versus 74%) when compared with physicians with predominantly White patient populations. Factors that appeared to contribute to the difference in prevention practice patterns include physician training and education, the socioeconomic status of the patients, and the time physicians spend with patients. Differences in quality of preventive care provided to minority patients may be an additional factor in the disparity between the health status of White and non-White Americans.