OBJECTIVE To compare the long-term follow-up growth of congenital, unilaterally palpable, undescended testes after orchiopexy according to age at the time of surgery. The optimal age for surgical treatment remains controversial. MATERIALS AND METHODS A total of 86 patients (108 testes) between the ages of 1 and 9 years underwent orchiopexy. Patients were divided according to age at the time of surgery: group I, <2 years (n = 43); group II, 2 <= age < 5 years (n = 35); and group III, >= 5 years (n = 30). The boys were then followed for more than 2 years after surgery. Ultrasonography was used for determination of testicular volume. Testicular volume percentage was compared by the equation of (operated testis volume/normal testis volume x 100%). RESULTS Testicular location was the inguinal canal in 92 (85.2%) and lower to the external inguinal ring in 16 (14.8%). Only group I, which received orchiopexy within two years from birth, showed significant recovery of testicular volume at follow-up (P <.05), compared with groups II and III. CONCLUSIONS Orchiopexy performed at less than 2 years from birth was a significant factor for recovery of delayed cryptorchid testicular growth. This result suggests that early orchiopexy improves subsequent testicular catch-up growth. UROLOGY 78: 886-890, 2011. (C) 2011 Elsevier Inc.