Fifteen women who reported a first-time rape had higher cytotoxic cells, lower B lymphocyte counts, higher proinflammatory biomarkers, and decreased lymphocyte proliferation compared to the control group of women who had not been raped. This finding suggests that rape activates the victim's innate immunity and suppresses some aspects of adaptive immunity. If this weakening of the immune system persists, it may contribute to the victim's vulnerability to long-term health problems by provoking chronic inflammation and decreased cellular immunocompetence. After approval from the University Institutional Review Board and the Sexual Assault Center, Sexual Assault Nurse Examiners recruited women who reported a first-time rape and had come to the center for help. The time frame following the rape was 24 to 72 hours. Fifteen participants agreed to participate in the study and were able to provide adequate volumes of blood for all sera analyses. The control group consisted of 16 healthy women who had not been raped and reported low levels of stress, no use of medication, and were in the follicular phase of their menstrual cycles, except for 1 postmenopausal woman. 3 figures, 1 table, and 30 references