Four family practices in the San Francisco Bay Area, two of which did not include obstetrics and two of which did, were examined with reference to their patient populations and to the number of families for which they provided comprehensive, continuous family care. The groups practicing without obstetrics were found to do acute care primarily and, to a lesser extent, long-term care internal medicine, with very little pediatrics or gynecology. The groups practicing with obstetrics did significantly more minor surgery, gynecology, pediatrics, and psychotherapy. During the six-week study, the group practicing with obstetrics saw five times as many patients who were members of families receiving continuous, comprehensive care from the practice under observation. Psychotherapy done by the group including obstetrics was primarily family therapy; for the other group, individual therapy. If larger studies support these findings, then important implications are suggested for training programs in family practice and for the resident deciding to enter practice.