Testicular germ cell tumors (TGCT) are rare malignancies which affect young adults and adolescents between the ages of 15 and 40 years. In suspected malignant TGCT, the treatment of choice is radical orchiectomy. However, in specific cases this routine surgical approach has been challenged in favor of an organ-preserving approach with comparable oncological outcome. Thus, testis-preserving strategies should be considered in unilateral or bilateral synchronous or metachronous TGCT as well as incidentally found small testicular masses, which are mostly benign lesions including Sertoli cell tumors, Leydig cell tumors, adenomatoid tumors or epidermoid cysts. In case of a testis-preserving surgery, adjuvant postoperative radiation therapy (20 Gy) is recommended. The rational for this approach is that the remaining parenchyma harbors germ cell neoplasia in situ (GCNIS), which might lead to locally recurrent TGCT in 50% in the next following 5 years. However, testicular radiotherapy might result in infertility and 'Sertoli-cell only' syndrome because of radiation-induced destruction of germ cells as well as Leydig cell insufficiency in 20% of all patients leading to life-long androgen substitution. Therefore, radiation therapy should be delay or sperm banking be should performed in fertile patients wish to have children. This review provides an overview on literature regarding testis-preserving strategies in TGCT as well as GCNIS.