In an effort to determine the factors underlying changes in obstetric practice by family physicians, a random sample of 505 residency-trained family physicians was surveyed by mailed questionnaire. Of the 329 who responded, 65% had at some time practiced obstetrics, but only 45% were practicing obstetrics at the time of the survey. Rising malpractice insurance premiums and fear of lawsuit were factors most likely to influence a family physician's decision to cease obstetric practice. Lifestyle concerns and the number of obstetricians practicing in the area were also important factors for all family physicians. Important differences were found between family physicians who never delivered babies and those who had at some time practiced obstetrics. Family physicians who have given up obstetric practice were found to feel well trained and competent in this practice. Since changes in obstetric practice patterns have had an adverse effect on the obstetric care of women in rural areas and for the medically indigent, these findings have important public health implications.