OBJECTIVE We dissected prevailing assumptions about cryptorchidism and reviewed data that support and reject these assumptions. METHODS Five questions about cryptorchidism and the risk of testicular cancer were identified because of their implications in parent counseling and clinical management. Standard search techniques through MEDLINE were used to identify all relevant English language studies of the questions being examined. Each of the 5 questions was then examined in light of the existing data. RESULTS The RR of testicular cancer in a cryptorchidism case is 2.75 to 8. A RR of between 2 and 3 has been noted in patients who undergo orchiopexy by ages 10 to 12 years. Patients who undergo orchiopexy after age 12 years or no orchiopexy are 2 to 6 times as likely to have testicular cancer as those who undergo prepubertal orchiopexy. A contralateral, normally descended testis in a patient with cryptorchidism carries no increased risk of testis cancer. Persistently cryptorchid (inguinal and abdominal) testes are at higher risk for seminoma (74%), while corrected cryptorchid or scrotal testicles that undergo malignant transformation are most likely to become nonseminomatous (63%, p <0.0001), presumably because of a decreased risk of seminoma. CONCLUSIONS Orchiectomy may be considered in healthy patients with cryptorchidism who are between ages 12 and 50 years. Observation should be recommended in postpubertal males at significant anesthetic risk and all males older than 50 years. While 5% to 15% of scrotal testicular remnants contain germinal tissue, only 1 case of carcinoma in situ has been reported, suggesting that the risk of malignancy in these remnants is extremely low.