A series of 161 boys with 178 impalpable testes is reviewed. Extended inguinal exploration was the main form of investigation and treatment. Hormone injections and studies were performed in bilateral cases. Sonography was unhelpful. Laparoscopy was not used. Impalpables testes account for 7% of all boys with an anomaly of testicular descent and 8.5% of operated boys. One hundred and twenty six testes were found, 58 in the abdomen, 68 in the inguinal canal. Thirty one nodular vestige were found and all 25 with histopathology were spermatic duct residue. In 21 boys no trace of testes or spermatic duct remnant were found. Ninety five testes were successfully brought to the scrotum with one (85) or two (10) stage procedure. Anomalies of the upper urinary tract in 13 of 21 cases without testes or spermatic duct remnant were very rare. In bilateral cases it looks better to search a testes whatever the biological responses to gonadotropin stimulation.