The professionalization of medicine in the twelfth and thirteenth centuries led to an exclusion of women practitioners from the best paid and most respected medical positions. Male doctors controlled the teaching and theory of women's medicine, and their gynecological literature incorporated male experience, understanding and learning. The treatises attributed to Trotula, which survive in nearly 100 manuscripts, were the most popular texts used by academic physicians in the later Middle Ages. Although Georg Kraut's Strassburg edition of 1544 treats the treatises of "Trotula" as a single, unified work, three separate texts circulated in the Middle Ages, and on stylistic and other grounds it is likely that each was written by a different author. Reasonably solid evidence demonstrates the existence of a woman physician at Salerno named Trota or Trotula, but she was not a magistra (as is often asserted), and it seems that she did not write even one of the three texts attributed to her. Instead, she produced a Practica from which extracts appear in a Practica secundum Trotam, which survives as a single mansucript in Madrid, and in De aegritudinum curatione in the Wrociaw (Breslau) Codex Salernitanus. This paper is to be published by the Bulletin of the History of Medicine in 1985.