Dehydroepiandrosterone (DHEA) exerts a variety of positive effects on the immunologic alterations after trauma and sepsis. We therefore measured the therapeutic efficacy of DHEA after cecal ligation and puncture (CLP) on the expression of lymphocyte subpopulations and on the delayed type hypersensitivity (DTH) reaction. Male NMRI-mice were randomly assigned to four different treatment groups. Treatment consisted of DHEA or saline (S) administration after CLP or laparotomy only. Flow cytometry was performed (CD4+, CD8+, and CD56+ lymphocytes) after 96 hours. DTH-reaction, activity and mortality rate were documented. The CLP-induced reduction in activity and survival (mortality: 34/40) was significantly (p < 0.03) less sustained in CLP-DHEA (mortality: 22/40). The DTH-ratio (before vs. after secondary challenge) was significantly lowered in CLP-S (1.01 ± 0.15) compared to CLP-DHEA (1.35 ± 0.1) after 48 hours (p < 0.01). CLP-DHEA (22.2 ± 7.9%) was associated with a statistically significant less sustained increase of CD56+ cells (p < 0.01) compared with CLP-S (49.0 ± 6.9%). DHEA-treatment after CLP was associated with less reduction in the CD8+ T-lymphocyte subsets (p < 0.01 vs. all other groups). DHEA treatment after CLP was associated with fewer alterations in the changes of CD8+ and CD56+ cells, and the DTH reaction compared with animals submitted to CLP without any treatment. This difference was associated with improved outcome (reactivity, mortality). These results suggest a modulation at specific immune reactions by DHEA treatment.