Gynecomastia is the development of abnormal breast tissue in men. Relatively increased estrogen action on tissue level is believed to play a main role in the pathogenesis of the entity. Here, we describe a patient with painless gynecomastia presenting after cytotoxic chemotherapy for testicular cancer. Further investigations showed no evidence of disease progression, recurrence, or metastasis. We suggest that the clinicians should be aware that gynecomastia may follow cytotoxic chemotherapy for testicular cancer and does not reflect the return of malignancy.