Introduction Human immunodeficiency virus (HIV) is widely prevalent in the U.S., with approximately 1.1 million individuals estimated as infected with the virus (Centers for Disease Control and Prevention [CDC], 2012). [...], Occasional cannabis use has been associated with increased antiretroviral therapy (ART) adherence and relief of HIV symptoms, while heavy use has been associated with low ART adherence and negative psychological symptoms. The purpose of the present study was to investigate differences between non-cannabis use (NC), nondependent cannabis use (C), and dependent use (CD) in terms of ART adherence and HIV symptoms/ART side effects. A cross-sectional sample of 180 HIV+ individuals (78.3% male) completed measures of substance use and psychopathology, medication adherence, and HIV symptoms/ART side effects. Adherence was also measured via pill count, viral load, and CD4 count. Results indicated that the CD group reported lower adherence and greater HIV symptoms/ART side effects than the other two groups, with no differences observed between NC and C groups. There is a clinical need to address dependent cannabis use among those prescribed ART. Further examination is needed to ascertain the functions of cannabis use among individuals with HIV. Keywords Cannabis * Marijuana * HIV * Adherence * Symptoms * Side effects