Efavirenz has now become commonly used to treat HIV infection. Neuropsychiatric disorders have been reported in patients treated with efavirenz. Several factors often make it hard to determine the cause of these disorders: HIV infected patients take many different drugs, they may suffer from various organ diseases, and may also be heavily affected by problems in their everyday life. The French experts group working on neuropsychiatric side effects of efavirenz has undertaken a review of these disorders with the aim to identify: (1) semiology, (2) epidemiology in the global population, in HIV infected patients, and in patients treated with efavirenz. The expert group suggests recommendations to manage these disorders.