J. Marion Sims (1813-1884) has been called the "Father of Gynecology" for his revolutionary approach to treating the diseases of women. He rose from humble origins to become a successful surgeon, teacher, and writer. His innovations included the first successful treatment for vesicovaginal fistula, the first gallbladder surgery, and the introduction of antiseptic principles in all areas of surgical treatment. The "Sims position" and "Sims speculum" are eponymic tributes to his accomplishments. In recent years Sims has, however, become a focus of controversy because of his experimental surgeries on slave women. His powerful personality and messianic attitude led him to minimize moral problems, and to bristle against opposition. Ethical principles of autonomy and beneficence are important criteria for evaluating Sims' research. An exploration of the nature of Sims' work and the atmosphere in which he practiced will illuminate the critical ethical questions surrounding Sims' use of slave women as experimental subjects.