Five of nine mule deer (Odocoileus hemionus) and all of eight white-tailed deer (O. verginianus) examined in central Arizona had microfilariae of Wehrdikmansia cervipedis (Wehr and Dikmans, 1935) in skin from the ear, but none in the blood, heart, lung, or skin from other areas of the body. These microfilariae, here described for the first time, averaged 224 μ long and 6 μ wide and had a sharply pointed tail. They do not have a sheath or an inner body. Adult W. cervipedis were found under the skin at the base of the ear in one mule and one white-tailed deer. The results suggest the ear may be the site of predilection for adults, as well as the microfilariae.