To determine the immunology kind of response Th1 (cytotoxic) or Th2 (humoral) prevailing at peripheral and peritoneal environment at endometriosis women (ENW).Observational, transverse, analytical, retrospective, cases and controls.Cooperative and cytotoxic lymphocytes obtained from peritoneal fluid (PF) and peripheral blood (PB) were used to determine IFN-gamma and IL-2 intracellular synthesis at ENW. IFN-gamma, IL-2, IL-4 and IL-10 concentration were determined at PF, PB at ENW and fertile women (FERW). Results were analyzed by ANOVA, t student and Mann-Whitney tests, accepting p < 0.05, as a statistic difference.Peritoneal environment of ENW shows a smaller intracellular synthesis of IFN-gamma and IL-2 at cooperative and cytotoxic T lymphocytes, as in the PF at ENW. The decrease is associated to a smaller percentage of activated, cooperative T lymphocytes and NK cells (p < 0.05, at all the variable), versus FERW. This phenomenon is observed more stressed at the III and IV pathology degree.ENW show a peritoneal environment with a smaller immunology cytotoxic capacity, versus FERW. The discouragement of the immunology cytotoxic capacity increases associated to the pathology intensity.