When a woman requests sterilization, how does her physician decide whether to operate? To answer this question, we analyzed the responses of 341 gynecologists to a survey consisting of clinical vignettes using a new statistical technique, conjoint analysis. The patient factors found to be statistically significant (all P less than .00005), in order, were age, parity/timing, and race. Other significant factors (all P less than .05) were marital status, family income, and educational level. Within those factors, physicians were most willing to sterilize older, postpartum, parous, black, married, poor, or well-educated women. Groups of physicians analyzed by age, gender, race, practice locale, practice type, religion, and religiosity were remarkably similar in their ordering. By a separate analysis, physicians were more willing to sterilize a diabetic woman than a woman in good health. This study supports the conclusions that factors including age, parity, timing, race, and health influence some gynecologists' decisions to sterilize and that not all gynecologists are willing to sterilize all patients.