Objective: To evaluate the efficacy of continuous positive airway pressure (CPAP) on serum testosterone in men with obstructive sleep apnea (OSA). Methods: Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before June 2014. Information on characteristics of subjects, study design, pre- and post-CPAP treatment of serum total testosterone, free testosterone and sexual hormone blinding protein (SHBG) was extracted for analysis. Results: A total of 7 studies with 9 cohorts that included 232 men were pooled into meta-analysis. There was no change of total testosterone levels before and after CPAP treatment in OSA men (standardized mean difference (SMD)= -0.14, 95% CI: -0.63 to 0.34, z = 0.59, p = 0.558), even subdivided by CPAP therapeutic duration (>3 months). Meanwhile, no significant differences in free testosterone and SHBG were detected after CPAP treatment (SMD = 0.16, 95% CI: -0.09 to 0.40, z = 1.25, p = 0.211 and SMD = -0.58, 95% CI: -1.30 to 0.14, z = 1.59, p = 0.112, respectively). Conclusion: CPAP has no influence on testosterone levels in men with OSA, further large-scale, well-design interventional investigation is needed.