Conduction velocities of single afferent fibers in the female rat hypogastric nerve were measured by stimulating dorsal rootlets and recording from the hypogastric nerve. A total of 344 units were identified and measured. They were distributed among dorsal roots T13 to L3 ipsilaterally (75%) and between L1 and L2 contralaterally (25%). Over 95% were found in the L1 plus L2 dorsal roots. Ninety-six percent of the units had conduction velocities less than 2 m/s; the average conduction velocity was 0.98 m/s. By way of contrast, afferents in the postganglionic nerves innervating the urinary bladder with conduction velocities less than 2 m/s constituted 65% of the afferents. We conclude that the overwhelming majority of afferents in the female rat hypogastric nerve are unmyelinated C-fibers.