Results concerning treatment of Testicular Germ Cell Cancer (TGCC) and subsequent risk of testosterone deficiency are conflicting. To systematically evaluate and estimate the risk of testosterone deficiency (TD) in TGCC-patients according to treatment to optimize follow-up and for prevention of late effects related to hypogonadism. We performed a critical review of PubMed in January 2015 according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Twelve publications were selected for inclusion in this analysis. Eleven studies evaluated the risk of TD in TGCC-patients treated with standard chemotherapy (CT) and the odds ratio for TD was 1.8 (95% CI) (1.3-2.5), (p = 0.0007). Seven studies evaluated the risk of TD in TGCC-patients treated with non-conventional therapy and the odds ratio for TD was 3.1 (95% CI) (2.0-4.8), (p < 0.0001). Six studies evaluated the risk of TD in TGCC-patients treated with infradiaphragmatic radiotherapy (RT), and the odds ratio for TD was 1.6 (95% CI) (1.0-2.4), (p = 0.03). In all treatment groups the risk of TD was compared with TGCC-patients treated with orchiectomy alone. There was no indication of heterogeneity between studies in the three treatment groups. Strong evidence exists that standard CT, non-conventional therapy and infradiaphragmatic RT are associated with an increased risk of TD in TGCC-patients when compared with orchiectomy alone. The risk of testosterone defficiency appears to be highest in patients treated with non-conventional therapy.