It is often assumed that family physicians are able to provide a higher quality of medical care because of the greater degree of continuity inherent in their practices. The authors attempted to measure the association between continuity and quality of medical care using pregnancy as a tracer condition. Using a retrospective cohort study design, two groups of pregnant women were identified--those cared for in the family practice (FP) centers and those cared for in the obstetric (OB) clinics. Process and outcome of medical care were measured along with patient satisfaction. Provider continuity, as measured by the SECON value, was much higher in the FP group, and was highly correlated with the presence of an "attitudinal contract" between patient and physician. Although not statistically significant, four times as many newborns from the OB group were admitted to the neonatal intensive care unit. FP group newborn weight averaged 220 grams more than the OB group (P less than 0.05). This difference remained after control for covariates. While not reaching statistical significance, patient satisfaction scores tended to be higher for the FP group in two of three categories measured. The results suggest that continuity of care was associated with better patient outcome and satisfaction. Directions for causal interpretation and future research are discussed.