We searched the Ovid databases, including AIDSLINE and MEDLINE from January 1, 1993, to November 30, 1999, using the following key words: "hepatitis C," "HCV," "HIV," "liver diseases," "drug toxicity," "antiviral therapy," "therapy," "interferon," and "vaccination." These key words were exploded and appropriate search combinations were performed. References were manually scanned for relevant articles published prior to 1993. Abstracts were included only if the complete data set was available to us. Relevant abstracts from the Seventh Conference on Retroviruses and Opportunistic Infections were also included. In this review article, patients with dual HIV/HCV infection are termed "coinfected patients" or "patients with HIV/HCV." Articles concerning perinatal transmission were selected when they included both HCV-infected and coinfected pregnant women, to ensure uniformity in patient selection and follow-up. Pooled relative risks of combined data were performed with Epistat Version 1991 (Epistat, Round Rock, Tex). χ2 Tests were performed using GraphPad Pris, Version 2.01 (GraphPad Software Inc, San Diego, Calif).