The purpose of this study was to assay the effect of two months exercise and two months silent on the levels of interleukin-17 (IL-17), melatonin and cortisol in serum, whole blood (WB) and peripheral blood mononuclear cells (PBMCs) cultures. Thirteen male non-athletic health volunteers participated in a two months moderate exercise program (running %50-%65 VO2 max). The blood samples were collected in three stages, 24 hours before to start exercise, 48 hours and two months after the last session of the training. WB and PBMCs were cultured with mitogens phytohemagglutinin and lipopolysaccharides for 48 hours. The serum and supernatants of WB and PBMCs were analyzed for IL-17, melatonin and cortisol by enzyme-linked immunosorbent assay. Red blood cells (RBC) variables were also measured. IL-17 secretion by PBMCs in the post-exercise stage (51.14±5.43 pg/ml) compared with pre-exercise (36.74±6.98 pg/ml) was increased. But, the amount of melatonin produced by PBMCs in the post- exercise (7.94±0.35 pg/ml,) and 2-month silent (6.05±0.27 pg/ml) stages compared with pre-exercise (9.16±0.19 pg/ml) were decreased. Regardless of the effect of the exercise, PBMcs had more ability to produce IL- 17 than WB. As well as, level of cortisol in WB was higher than in serum and PBMCs culture. Mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration RBCs were also increased in post- exercise stage. The other measured parameters were not changed during exercise and recovery. Moderate exercise caused to higher in vitro production of IL-17 and lower production of melatonin by PBMCs.