The effect of a chromone-containing allylmorpholine derivative in three dose ranges (1 mg/kg, 10 mg/kg and 50 mg/kg) on the behavior of BALB/C mice in the Elevated Plus Maze test was evaluated. A dose of 50 mg/kg induced a sedative effect in the tested animals, as evidenced by a decrease in the number of crossed squares, rearings and closed arms entries compared to the control group. The effects of dose of 10 mg/kg were similar to those of classical anxiolytic drugs (increased number of entries and total time in the open arms), but in all cases, there were no significant differences compared to the control. Thus, in the present work, the previously shown sedative effect of allylmorpholine 33a in zebrafish was confirmed. The probable anxiolytic activity of this compound requires further investigation.