Although medical research has been criticized for gender bias, few studies have dealt with how such bias affects medical education and textbooks. There is an extensive body of literature showing that most scientific research has been performed by men on men or on male laboratory animals. The male is often considered the norm, the female the exception. This probably has a significant impact on the training of medical students, which is often gender biased, as well as on medical practice. A few studies have actually evaluated medical textbooks from a gender perspective, but a standard instrument or protocol is needed for such assessment. The present work, which was commissioned by a Swedish university, entailed the construction of an instrument that will facilitate gender analysis of medical textbooks.