Nevirapine is the first member of a new therapeutic class (NNRTI: non nucleoside inhibitors of the reverse transcriptase) in the treatment against human immunodeficiency virus (HIV). In association with two other antiretroviral products, it reduces significantly the viral load and increases the CD4-cells-count, especially in naive patients. Results at six months show that a tritherapy including nevirapine and 2 nucleoside inhibitors of the reverse transcriptase (NRTIs) has a similar efficacy than an association including 1 anti-protease and two NRTIs. Nevirapine is easy to take (1 tablet 2x/day, irrespective of the meals). Its tolerance profile is favourable. The principal side effect is a rash, which can be severe in rare cases.