Background: To evaluate the role of human chorionic gonadotropin  (HCG) in cryptorchid boys regarding testis position and size in treatment of palpable undescended testis (UDT). Patients and methods:  One hundred children presented with unilateral palpable UDT were studied in the period from May 2007 to May 2010. Their ages ranged from2-12 years with mean age 6.4 years SD ±2.1 and were divided into two equal groups: Group A- {control group) in which surgical orchidopexy was done without preoperative hormonal  preparation and Group B- {studied group) in which the patients received preoperative intramuscularinjection of HCG 30-50IU(Pregnyl) per kilogram ofbodyweight, two times a week for five succeeding weeks. The patients were subjected to clinical examination, laboratoryinvestigationsincluding testosterone level pre- and post- HCG therapy, ultrasound (UIS) and color Doppler ultrasound (CDUS). The results were assessed clinically, hormonal level, and CDUS  Standard orchidopexy was done in all cases. Both groups were assessed in teims  of testicular size and vascularity by CDUS  The mean basal and post-HCG stimulation  serum testosterone level were also compared in both groups. Both groups were also followed up postoperatively, clinically and by UIS Results:   found sizable testis, long cord withgood vascularity, easily dissectible associated hernial sac and more capacious scrotum with good post-operative results in group B patients. Conclusion: Preoperative HCG treatment is a safe effective tool to increase testicular size and viability which improve the results of orchiopexy