This third paper on Malaysian Cyperaceae chiefly discusses new and otherwise noteworthy species of Fimbristylis. In addition a key to the Malaysian species of the genus and a survey of their arrangement as accepted for the Flora Malesiana are given. A few new species are described from Siam and Indo-China. I am greatly indebted to the Directors of the Herbaria who granted me the opportunity to study the collections of their institutions.