Anxiety is an emotional reaction frequently shown by students when a human cadaver is being dissected. Nonetheless, few studies analyze the nature of the anxiety response in this situation and the ones that do exist are mainly limited to English-speaking countries. Our research has three aims: to study the characteristic anxiety reaction to dissection practices, to determine the weight exerted by internal and environmental variables on this anxiety reaction, and to design practices aimed at reducing the state of anxiety experienced by pupils in their human anatomy practices. The studies were carried out in the dissection room of the Department of Human Anatomy and Embryology II at the Faculty of Medicine of the Complutense University, Madrid, during the 3 academic years 2000–2003. The anxiety response to the first dissection of a human cadaver is mainly determined by a situation considered to be threatening, with novelty as its main characteristic. The students' anxiety response is first determined by the situation itself and reactions depend on individual differences. Repeated or gradual exposure (detailed verbal information on the situation, visits to dissecting rooms when no cadaver is present, videos showing pictures of human dissections, etc.) before carrying out the first dissection reduce the students' anxiety response. Anat Rec (Part B: New Anat) 279B:16–23, 2004. © 2004 Wiley-Liss, Inc.