Cryptorchidism affects 0.8 % of male children at the age of one year. In approximately 20% of these children the testis will be impalpable and presumed to be located within the abdominal cavity. Numerous techniques have been developed to try to localize the impalpable undescended testes preoperatively. These techniques include: Ultrasound, computed tomography, magnetic resonance imaging and gonadal venography and anteriography. In this thesis the anatomy, embryology, development and descent of normal and cyptorchid testes, complication of undescended testis and management of the impalpable testis were reviewed. In addition 28 impalpable testes in 21 patients were treated (the testes were on the left side in seven patients on the right side in seven patients and bilateral on seven patients). A thorough history, local and general examination, scrotal and pelviabdominal ultrasonography, CT scan or MRI were carried for each patient. Also selective testicular venography was done to study the vascular pattern of the impalpable testes. Laparoscopic localization and laparoscopically –assisted orchidopexy were done for each patient. The result showed that localization of the impalpable testes using ultrasonography is unreliable. While computed tomography and magnetic imaging are more accurate than U/S. Laparoscopic is 100% reliable as a diagnostic tool for localization of impalpable testis. Selective testicular venography is useful in some cases and showed satisfactory results in high percentage of cases in spite of being an invasive technique. Laparoscopic-assisted orchiopexy proved to be the ideal surgical technique for management of the impalpable testis. It allows careful localization, dissection, mobalization and descent of the impalpable testis. This technique is highly recommended for management of the impalpable testis.