Objective. To evaluate efficacy and safety of injectable extended-release naltrexone (XR-NTX, Vivitrol), an opioid receptor antagonist, in the treatment of opioid dependence, we carried out a 1-year open-label extension study. Material and methods. The study followed the initial 6-month randomized, double-blind, PBO-controlled investigation of XR-NTX, used in dose 380 mg, as a treatment for opioid dependence. The study was conducted at 13 clinical sites in Russia. The main measurements were monthly urine samples (efficacy) and adverse events (safety). Results and сonclusion. The open-label extension included 114 patients (67 continued on XR-NTX and 47 switched from placebo). Overall, 62.3% (95% CI: 52.7%, 71.2%) of patients completed the extension. Urine testing revealed that 50.9% (41.5%, 60.4%) were abstinent from opioids at all assessments during the 1-year open-label phase. Adverse events were reported by 21.1% of patients. Elevations in liver function tests occurred in 16.7% of patients. No severe adverse events were reported. The data obtained demonstrate the long-term safety and efficacy of XR-NTX in opioid dependent patients.