Abstract: Present study was conducted to evaluate patients for the influence of age -sex on the pattern of modulation of selected immune parameters, following surgery. Male patients, of varying ages, without any underlying immune depression and needing minor to moderate dissection were recruited randomly into the study following informed consent. They were placed in each of two groups: group 1 (GRP1) = ages 0.1 to 12 years and group 2 (GRP2) = ages 13 to 50 years. Blood samples were obtained 1) immediate preoperatively and 2) immediate postoperatively in every case and assessed for T-cell count, lymphocyte viability, B-cell count, total leukocyte count, total lymphocyte count and percentage lymphocyte transformation. T-cell counts and percent lymphocyte transformation alone were significantly different postoperatively but not preoperatively for both groups (p=0.023 and 0.031, respectively). All other parameters were not. Postoperative values for T-cell counts and lymphocyte transformation were, however, lower than their corresponding preoperative levels. The results have shown that age-sex influences immune parameters such as T-cell population and function after, but not before, surgery suggesting the possible involvement of background gonadal neuroendocrinologic influences in the immune response to surgical stress.