Opinions about a four-year family practice residency were elicited from a nationally representative sample of three groups of family physicians. Questionnaires were mailed to a random sample of 308 residency graduates aged 30 to 35 years, all 383 residency directors, and a random sample of 319 third-year residents. Two mailings produced an 82 percent response rate. A four-year residency was favored by 32 percent of recent graduates, 20 percent of program directors, and 34 percent of third-year residents. Over 60 percent of residents and recent graduates would have entered a family practice program had the residency been of four years' duration. Perceived barriers to a four-year residency included lack of resources, loss of appeal, and the additional time commitment. Respondents were most willing to complete a fourth year of residency to receive additional training in orthopedics, obstetrics, gynecology, and pediatrics. Many respondents believed that the additional year would be helpful in obtaining hospital privileges in obstetrics and in coronary care and intensive care units. This study provides information useful in discussions regarding extending residency training.