Morus nigra has been used to relieve pain in Brazilian folk medicine. This study was conducted to establish the antinociceptive properties of dichloromethane extract from leaves of M. nigra. The formalin, hot plate, and tail immersion tests as well as acetic acid-induced writhing were used to investigate the antinociceptive activity in mice. The extract at test doses of 100 and 300 mg/kg, p.o. clearly demonstrated antinociceptive activity in all tests. The extract administered at 300 mg/kg, p.o. had a stronger antinociceptive effect than indomethacin (5 mg/kg, p.o.) and morphine (10 mg/kg, p.o.), which supports previous claims for its traditional use.