In male cancer patients, surgery, radiotherapy and chemotherapy can be followed by transient or permanent infertility by affecting ejaculatory or erectile function, or by impairing spermatogenesis. Cancer specialists should, therefore, discuss the impact of different therapies on fertility with their patients prior to treatment, and consider fertility-preserving measures before and during treatment, such as nerve-sparing operative techniques, adequate testicular shielding during radiotherapy and the avoidance of unnecessary gonadotoxic chemotherapy. Pretreatment sperm-cell cryopreservation should be offered, even in cases where the individual's risk of post-treatment infertility might seem minimal or if it might require testicular sperm-cell extraction. Samples that are severely oligospermic should also be cryopreserved. Post-treatment ejaculatory or erectile dysfunction can be reversed pharmacologically, but the success rate varies with the extent of neurologic sequelae of the treatments used. At present there is no established method to stimulate post-treatment impaired spermatogenesis, although currently available assisted reproductive techniques overcome some of the existing problems of infertility in cancer survivors, and ongoing research will hopefully increase these possibilities. A multidisciplinary approach that depends on close cooperation between relevant medical specialists is central to achieving such advances.