AIDS is a serious infectious disease caused by a new family of retrovirus which is spread primarily through sexual contact and administration of blood or blood products. Individuals who are infected with HIV could therefore benefit from therapy with an effective anti-AIDS virus agent. AZT and ddC have both been tested as antiviral agents and their potentially beneficial effects may be limited by time- and dose-dependent toxicity. A combination regimen using shorter courses of AZT and ddC might therefore be able to sustain treatment without producing toxicity. In addition, since the two drugs exhibit their major toxicity on different organ systems, cumulative or additive toxicity would not be expected.