A method and apparatus (10) for processing chopped fibers (12) from essentially continuous tows (18a, b, c), each consisting of individual strands (20), comprises independently feeding at least two tows to a venturi pump (22) and associated cutter mechanism (24) where the tows are cut or chopped into relatively short lengths to form chopped fibers. The apparatus includes sensors (84) for monitoring the movement of each of the tows to the pump and cutter mechanism, and a controller (28) which adjusts the feed rate of the tows and the rate of operation of the cutter mechanism in the event movement of one of the tows varies from a predetermined feed rate.