BACKGROUND Testicular cancer treatment has become standardized in the 1980s involving radiotherapy preferentially for seminoma and chemotherapy for nonseminoma. The late effects of these therapeutic practices have not been properly evaluated because of the relatively short time since their application. PATIENTS AND METHODS We conducted a study among 5533 survivors of testicular cancer on the basis of Swedish Family-Cancer Database for which the cancer data were retrieved from the nationwide Cancer Registry. Standardized incidence ratios (SIRs) of second cancer were calculated by comparing with the rates of the first cancers. The follow-up was started in 1980 and carried on through 2006. RESULTS A total of 370 second cancers (6.7% of all patients) were recorded, more in seminoma than in nonseminoma patients. Second testicular cancer showed an SIR of 29 after seminoma and an SIR of 13 after nonseminoma. A total of 10 discordant sites were increased after seminoma compared with seven sites after nonseminoma. Gastrointestinal tract cancers occurred mainly after seminoma and bladder cancers (SIR 8.6 when diagnosis before age 30) occurred after nonseminoma. CONCLUSIONS Of the selective affected second tumors, it will be important to confirm the association of bladder cancer with nonseminoma treatment.