Morinda citrifolia Linn. (Rubiaceae) (Noni) is a plant, to which several therapeutic properties have assigned, but its neuropsicopharmacological effects have been poor studied. The aim of this work was to characterize the neuropharmacological properties of its juice, in male mice, by means of a battery of behavioral tests: Irwin test, exploratory behavior, barbiturate sleeping time and amphetamine-induced stereotypes. Doses of 450, 900 and 1800 mg/kg were administered, according to the juice dry weight. The results obtained from the different tests suggest the presence of non identified chemical compounds with sedative activity, specifically of neuroleptic type.