Aronia melanocarpa fruit juice (AMFJ) has been intensively studied for effects on the central nervous system. The study aimed to investigate AMFJ for possible sedative-hypnotic effects in rats after acute and subchronic administration. Male Wistar rats were treated orally with three doses of AMFJ (2.5, 5.0 and 10.0 ml/kg) either once (acute treatment) or in 30 days (subchronic treatment). Control rats were similarly treated with distilled water. The tests were performed 1 hour after the last AMFJ administration. The possible sedative-hypnotic effects of the juice were investigated in the open field test (OFT) and thiopental-induced sleeping time test. Substances with sedative-hypnotic effects decrease locomotor activity in the OFT and prolong the time of thiopental-induced sleep. The results from the OFT showed that neither the acute, nor the subchronic treatment of rats with all AMFJ doses affected the horizontal and vertical locomotor activity significantly. The two patterns of administration of AMFJ (acute and subchronic) had no significant effect on the duration of thiopental-induced sleep. The lack of effect of AMFJ on locomotor activity and the lack of prolongation of thiopental-induced sleep showed that AMFJ did not display sedative-hypnotic effects in rats.