The dichloromethane fraction from Areca catechu was found to inhibit monoamine oxidase type A isolated from the rat brain with an IC50 of 665 +/- 65.1 microg/ml. Studies with pharmacological models of depression, i.e., forced swim and tail-suspension tests, indicated that it caused significant reduction in the immobility time similar to that of moclobemide (a selective inhibitor of MAO-A) without causing a significant change in motor performance. Alkaloids such as arecaidine, arecoline, and a few other constituents, reported to be present in Areca catechu were also tested, but none of them were found to inhibit MAO. Present study suggests that the dichloromethane fraction from A. catechu possesses antidepressant property via MAO-A inhibition.