In 10 cats, an ipsilateral section of the inferior alveolar nerve was performed following which horseradish peroxidase was deposited in cavity preparations of either ipsicentral incisors (8) or canines (2). The animals were sacrificed in 24 h, and the ipsilateral nerve to mylohyoid and both semilunar ganglia were prepared histochemically for observation. Labeled axons were found in 6 of 8 cats, whose incisors were prepared, and 4 of the 6 had labeled ganglion cells. In the two remaining cats with incisor preparations, no labeled ganglion cells were found; however, labeled axons were found in the mylohyoid nerve. Neither labeled axons or cells were found in those cats whose canines were prepared. One case of cross-innervation was noted. These results suggest that in addition to the inferior alveolar nerve, the nerve to mylohyoid and possibly other accessory neural pathways are involved in incisor innervation in cats.