Because most children and adolescents with cancer now survive, issues regarding the late effects of therapy, including fertility and the health of offspring, are increasingly important. This article summarizes the literature regarding issues related to fertility in survivors of cancer, including actual fertility, gonadal function, menarche, menopause, and birth defects and cancer in the offspring. Radiation therapy to the gonads and alkylating agent chemotherapy, either alone or in combination, impair actual fertility in survivors of childhood and adolescent cancer. Males are particularly affected by alkylating agents, and females who have had radiation therapy to the abdomen have decreased fertility and an increased risk of adverse pregnancy outcomes. Consequently, these women should be followed up as high-risk obstetrical patients. Offspring of survivors of cancer appear to have little risk of childhood cancer or birth defects. Thus, in most instances, survivors of cancer should not be discouraged from having children and can expect a good outcome of pregnancy. This article concludes with advice to survivors and clinicians who counsel survivors.