Background/aim: It is accepted that red blood cell distribution width (RDW) is a novel prognostic marker that reflects oxidative stress and chronic inflammation. In this study, we aimed to investigate the correlation between RDW and varicocele, the etiology of which has not fully elucidated yet. This study also aimed to study the mean platelet volume (MPV) values of the patient and control group. Materials and methods: RDW and MPV levels were measured in 50 varicocele subjects (group 1) and 48 healthy controls (group 2) from January 2012 to January 2014, retrospectively. Results: MPV levels were significantly higher in group 1 than in group 2 (P < 0.001). Although the relationship was weak, the patients with varicocele had significantly lower RDW values than did the controls (r: 0.24 P = 0.026). Positive correlations were not found between varicocele grade and MPV and RDW values (P < 0.05) Conclusion: Higher MPV values are associated with increased odds of developing varicocele.