An aqueous extract of Luffa operculata Cong. Cucurbitaceae (Cabacinha) was tested in mice for the following pharmacological effects: toxicity, analgesia (“grid shock” method), alteration of neuromuscular coordination (rotarod), and modification of barbiturate metabolism (hexobarbital sleeping time). The extract was evaluated in rats for analgesic effects (heat method); effects on electroshock seizure threshold; effects on blood pressure, pulse, electrocardiographic, and respiratory patterns; and anti-inflammatory activity. It was tested in guinea pigs for protective effect against histamine-induced bronchospasm. The extract was found to be inactive in all except analgesic studies in mice, in which a significant elevation of pain threshold was seen with 160 mg/kg ip. The 24-hr LD50 of the extract in mice was 160 mg/kg ip. A possible mechanism of the action is discussed.