Positive effects on reducing students' stress have been reported across numerous university settings when anatomy preparatory seminars have been provided. To date, this type of preparation for coping with cadaver dissection has not been studied in Spanish universities. The aim of this study is to evaluate how first-year Spanish medical students face the dissecting room and whether previous preparation about death and dying reduces the stress generated. We performed an interventional study with students who received preparatory classes before the dissection practices (Experimental Group, EG) and with students who did not (Control Group, CG). Sociodemographic data and a self-assessment on stress symptoms were collected through a questionnaire completed before and after the dissection practices. No differences were found in the self-report of symptoms of stress among students who consider themselves religious or not, or between students who had a family member in the healthcare environment or not. However, in the EG, the students who had ample experience with terminally ill patients or death reported fewer stress symptoms. Unexpectedly, the number of selfreported stress symptoms after the dissection practice was higher in EG students. In conclusion the stress levels of first-year Spanish medical students not only did not improve after receiving preparatory classes about death and dying and discussion groups, but it gets worse. We found a relationship between student stress measured and experience with terminally ill patients or death. Additional studies are needed to identify the most suitable preparation for Spanish medical students.