The non-nucleoside analog reverse transcriptase inhibitor efavirenz is one of the most common components of HAART. Neuropsychiatric symptoms are frequently reported in patients taking efavirenzbased regimens. These symptoms are usually transient, although they can sometimes persist for up to two years after initiation of treatment. This review describes in detail the most common neuropsychiatric symptoms related to efavirenz, outlines relevant and recent findings on this agent, and suggests possible interventions based on neurobehavioral results. Different recommendations on the assessment of efavirenz-related adverse events are also provided.