An investigation of pasture-reared pigs experimentally infected with Oesophagostomum dentatum and Hyostrongylus rubidus showed that daily doses in the feed with the microfungus Duddingtonia flagrans over a 2-month period led to lowered herbage larval infectivity of both species. This was further substantiated by low worm recoveries in initially parasite-naive tracer pigs that were later introduced to the pasture plot. The control setup comprised the release of similarly infected but nondosed pigs on a plot of the same area, followed by a group of tracer pigs. This paper discusses the potentials for using this biological control principle in the pig industry and emphasizes the research required, primarily regarding production technology and elaboration of feasible epidemiology-based dosing regimens, before such control can be implemented in practice.