The risk of chemotherapy-induced infertility in male and female germ cell tumour (GCT) survivors is unclear, but may correlate with cisplatin dose. Here, we examine a large series of GCT patients for the effect of chemotherapy on those attempting to have children. Our GCT database was screened for nonseminomatous GCT patients who had ( 1) received POMB/ACE chemotherapy ( cisplatin, vincristine, methotrexate, bleomycin alternating with actinomycin D, cyclophosphamide and etoposide) and ( 2) stage I male GCT patients who were untreated between 1977 and 1996. Fertility was assessed by questionnaire and medical records. A total of 64 of 153 treated and 35 of 115 untreated men attempted to have children. In all, 28% ( 18 out of 64) receiving POMB/ACE were unsuccessful. Radiotherapy ( six), atrophic remaining testis ( one) or prior infertility ( three) were implicated in 10 cases, so chemotherapy-induced infertility may have occurred in only 11% ( eight out of 64). Strikingly, 26% ( nine out of 35) of untreated stage I patients also failed to have children ( three had radiotherapy, three prior infertility). Moreover, in treated men, no association was seen between cisplatin dose and infertility. In contrast, radiotherapy significantly increased male infertility ( P = 0.001). Of 28 treated women who attempted to have children, 25% ( seven out of 28) were unsuccessful. One previously had infertility and one subsequently had successful IVF so chemotherapy-induced infertility potentially occurred in only 18% ( five out of 28) and was not related to cisplatin dose. In conclusion, the risk of chemotherapy-induced infertility is low in both male and female GCT patients and does not clearly correlate with the cumulative cisplatin dose.