OBJECTIVE The pharmacology, efficacy, and safety of etravirine and its clinical utility with respect to the available alternative human immunodeficiency virus (HIV) treatment options are reviewed. CONCLUSIONS While single mutations confer resistance to earlier nonnucleoside reverse transcriptase inhibitors (NNRTIs), etravirine exhibited an increased barrier to resistance by requiring multiple mutations for resistance to occur in preclinical studies. Randomized controlled trials have demonstrated the efficacy of etravirine in achieving HIV RNA viral loads of <50 copies/ mL and a significant increase in baseline CD4+ lymphocyte count in treatment-experienced patients. There has been a trend toward increased rates of death, progression to acquired immunodeficiency syndrome, and opportunistic infections in patients using placebo during Phase III trials. Baseline patient characteristics that correlate with changes in etravirine efficacy are reported. Mild-to-moderate rash and nausea are the most common adverse effects of etravirine. If rash is suspected, etravirine should be discontinued and rechallenge should be avoided due to the risk of severe and possibly fatal skin reactions. Unlike some antiretrovirals, increased risks of hepatic, lipid, or neuropsychiatric abnormalities are not correlated with its use. Several drug interactions are expected with etravirine use, and some may require dosage adjustment or substitution of concurrent drugs. No dosage adjustments are recommended for patients with mild-to-moderate hepatic or renal impairment. CONCLUSIONS Etravirine, a second-generation NNRTI, is efficacious in achieving viral suppression and improving the immune function in treatment-experienced HIV-infected patients.