In order to investigate the combined use of radioprotective and radiosensitizing chemicals we have used WR-2721 and misonidazole to study their combined chemical toxicity and radiomodifying effects in our model using the oral radiation death (ORD) syndrome as the endpoint. Our data demonstrate that WR-2721 does protect against the ORD syndrome. Misonidazole does not sensitize the normal oral cavity to local irradiation. WR-2721 and misonidazole produce additive toxicity when injected simultaneously and the combination can provide an overall protective response to the ORD syndrome. We conclude that the combination may be potentially useful for the treatment of cancers of the oral cavity.