Convergence of cardiac and cutaneous afferents onto neurons in the dorsal horn of the spinal cord was demonstrated in the cat. Responses of neurons to cutaneous stimulation revealed that they were either nociceptive specific (NS) or wide dynamic range (WDR) neurons. NS neurons were located in lamina I and outer zone of lamina II (IIo). WDR neurons were located in laminae I and IIo as well as laminae IV-VI. Since all the neurons responsive to electrical stimulation of the inferior cardiac nerve responded to cutaneous nociceptive input, it was inferred that the sensation evoked by excitation of dorsal horn neurons by cardiac afferents is pain. The observed convergence is suggested as a mechanism for referred pain, and convergence onto WDR neurons provides an explanation for the phenomenon of allodynia in a stage between anginal attacks.