Despite extensive literature on both herpes zoster and herpes simplex, there seems to be little accurate knowledge as to the exact nature of these conditions. This becomes apparent when one reviews the writings of various authors and one's own experience in a critical manner. The case reported here was unique in our experience, as herpes zoster and herpes simplex occurred simultaneously and seemingly as the result of the same infection. While this may have been coincidence, we did not wish to accept it as such owing to the rather striking course of events. The occurrence gave rise to much speculation on our part and caused us to review the literature in the hope of crystallizing our conception of the nature of these dermatoses. It must be said frankly that the result of that review was not satisfactory to us. It is offered, nevertheless, in the hope of