A number of single neurons in the dorsal column nuclei (DCN) and the sensory trigeminal nuclear complex were found to project to the thalamus and the inferior colliculus (IC). In the rats which were injected unilaterally with tetramethylrhodamine-dextran amine (TMR-DA) and Fluoro-Gold (FG) respectively into the posterolateral ventral thalamic nucleus and the external nucleus of IC, a number of neuronal cell bodies labeled retrogradely with both TMR-DA and FG were found throughout DCN contralateral to the injections. A few double-labeled neurons were also seen in the caudomedial part of the gracile nucleus ipsilateral to the injections. The double-labeled DCN neurons had relatively small cell bodies which are oval or fusiform in shape. When the injection sites in the thalamus extend into the posteromedial ventral thalamic nucleus, a few double-labeled neuronal cell bodies were seen contralaterally in the trigeminal sensory nuclear complex, mainly in the caudal part of the interpolar spinal trigeminal nucleus.