Objective. To analyze efficacy and safety of dexmedetomidine for postoperative sedation in cardiac patients. Material and methods. The study included 96 patients aged 18—70 years after elective on-pump cardiac surgery. The sedation protocol included an initial dexmedetomidine infusion rate of 0.7 mcg/kg/h for 60 minutes followed by dose adjustment until the sedation level was reached RASS score 0— –3. The maximum infusion rate of dexmedetomidine should not exceed 1.4 mcg/kg/h. In addition to sedation level, we assessed duration of residual effect of dexmedetomidine, severity of pain sensation (VAS score), need for administration of other sedative drugs, influence on blood pressure, heart rate, respiratory rate and sPO2, duration of mechanical ventilation and ICU-stay, as well as any adverse events. Results. Infusion of dexmedetomidine at a dose of 0.7 mcg/kg/h in cardiac patients on mechanical ventilation ensured target sedation level in 30 minutes after infusion onset. A good analgesic effect resulted significant 2-fold reduction in the VAS score of pain severity and 3-fold decrease of the incidence of pain severity ≥5 scores. Dexmedetomidine in mean therapeutic doses (0.2—0.7 mcg/kg/h) does not cause significant hemodynamic disorders in the majority of patients that is confirmed by the absence of arterial hypotension, rare episodes of bradycardia (6.3%) and other side effects. Thus, dexmedetomidine is safe for sedation in cardiac patients.