Connarus fulvus Planch is populary utilized in the State of Goiás because it is said to be "good for the heart". This paper studied the pharmacological activities of the crude ethanolic extract (EE) of the powdered bark and of the hirosoluble fraction (HF) of the benzine/water partition. The EE and HF produced in rats andmices a decrease in locomotion, certain drowsiness, respiratory problems, insensitivity to pain and weakness of the posterior limbs. These effects were proportional to the administered doses. The DL50 in mice were 210+/-22 and 310+/-52mg/kg, i.p. for the EE and HF, respectively. The HF potenciated barbiturate - induced sleeping-time, reaction time to heat in the hot-plate and, in 80% of the cases, it antagonized the convulsive actions of PENTYLENETETRAZOL but not of STRYCHNINE. It protected the mice, in all of the cases, against the lethal action of PANCURONIUM and potenciated the action of SUCCINYLCHOLINE. in isolated tissues the HF potenciated, in 20% of the cases, contrations of the diaphragm in response to electrical stimulus of the phrenic nerve of the rats and reversed the neuromuscular blonde produced by d-TUBOCURARINE. In rat and guinea pig atriums electrically stimulated neither the chronotropism nor inotropism were altered. The injection of EE nor HF in rats under anesthetics produced hypotension (5 to mg/kg) while higher doses were lethal. The data obtained from studies didn't confirm direct action on the heart. The plant thus presented depressive action in the CNS, analgesic and anticonvulsive action while, it also annuled the effect of CURARE.