Background: Signal transduction induced by cytokines, which stimulates cell growth, proliferation, differentiation of germ cells, spermatogenesis, reproductive and testicular function. Objectives: The aim of this study is to evaluate seminal plasma as well as serum IL 17 levels in infertile male patients compared with fertile male with normal semen parameters. Patients and methods: This study is across-sectional case-control study that has been conducted on 40 infertile male patients and 10 fertile males as a control group, The patients were divided into four groups; group (A) included 10 patients with azoospermia, group (B) included 10 patients with oligozoospermia, group (C) included 10 patients with asthenozoospermia and group (D) included 10 patients with oligoasthenoteratozoospermia (OAT). All the patients in the four groups and the control group (E) are subjected to routine semen analysis and seminal, serum IL-17 was measured. Results: Seminal level of IL-17 is significantly reduced between control and patient groups . The mean is from (2.83 ± 0.6) to (11.19 ± 1.6) in azoospermia, (9.14 ± 2.3) in oligozoospermia, (9.25 ± 2.2) in asthenozoospermia and (10.88 ± 1.4) pg /ml in OAT group  respectively, and (p= 0.004), The mean is from (25.31 ± 2.9) to (84.26 ± 10.0) in azoospermia, (78.51±6.6) in oligozoospermia, (65.60 ± 10.8) in asthenozoospermia and (82.43±8.5) pg/ml in AOT group respectively, and (p< 0.001).  A significant negative correlation is found between seminal interleukin 17 level and the sperms count, concentration, Sperm total and progressive motility (r= -0.398, r = - 0.366, r = -0.429 and r = -0.394). And asignificant negative correlation is found between serum interleukin 17 level and the sperms count, concentration present in infertile men respectively (r= -0.338 and r = -0.341), and (p< 0.001). Conclusion: IL-17 plays an important role in male infertility and it had a negative correlation with sperm parameter.