Using retrograde degeneration, the motor neurons of the urethral branch of the pudendal nerve, which supplies the external urethral sphincter, were located in the ventral part of the ventral horn in the sacral spinal cord of the cat. Two cell groups, partially fused into one column could be delineated. The more rostral and lateral group was usually in the S1 segment, while the more caudal and medial group was usually in the S2 segment. Chromatolysis in dorsal root ganglia indicated that afferents were distributed in approximately the same way as efferents. Recording evoked responses from dorsal and ventral rootlets disclosed some variation with the column occasionally extending into the L7 or S3 segments. The center of the column was usually near the junction of S1 and S2, extending for approximately 2 segments. The separation which sometimes occurred in the middle of the column should be considered if microelectrode studies of these cells are attempted. The origin in the spinal cord of the urethral branch of the pudendal nerve overlaps the origin of the pelvic nerve to the detrusor in the S2 segment in the cat.