Background: Germ cell testicular cancer (TC) patients have an increased risk of developing a contralateral TC. This paper presents a retrospective analysis of patients with bilateral TC from a database of a single center and aims to highlight the need for an individual approach. Material and Methods: In the study period from January 1970 to June 2013, a total of 1,438 patients with primary TC were diagnosed. The group comprised of 1,370 patients with unilateral TC and 68 patients with bilateral TC. Bilateral TC patients were evaluated regarding the age at presentation and the histology of tumor and then compared with the group of patients with unilateral TC. Results: The mean age of the patients with unilateral TC was 31.7 years. This group of patients consisted of 408 patients with seminoma and 962 patients with non-seminomatous TC. The group of 68 patients with bilateral TC involved 63 patients with metachronous disease and five patients who developed TCs simultaneously. The mean age at diagnosis of primary tumor in patients with metachronous bilateral TC (25.8 years) was significantly earlier in comparison to patients with unilateral disease. Among 24 patients with seminoma there were 17 patients who subsequently developed a second malignancy of an identical histological type. In the group of 39 patients with initial non-seminomatous TC there were 15 patients with discordant histology of the second tumor. In the metachronous disease group, patients with primary seminoma were significantly older than those with initial non-seminomas. Conclusions: All patients with unilateral TC have an increased risk of developing a contralateral TC, years and even decades after the initial diagnosis. Management of subsequent TC should be individualized for each patient according to the histology and clinical stage of the primary tumor, as well as the therapeutic strategy applied initially. The further management should involve a long-term follow-up and life-long testosterone substitution.