Foreign material extractors were installed and evaluated in farmers stock peanut flowpipes during the harvest seasons of 1978, 1979, and 1980. Three of the extractors evaluated were commercially available and consisted of a stationary, inclined screen manufactured by Suffolk Iron Works, Inc., Suffolk, VA; an inclined, mechanical tumbler-extractor manufactured by Hobbs-Adams Engineering Company, Suffolk, VA; and an inclined, mechanical roller screen manufactured by Bev. Mathison's Spring Works, Warwick, Queensland, Australia. Two additional experimental extractors including a stationary, inclined screen and an aspirator were also tested along with aspiration hoods used in conjunction with the commercial extractors. The weight per tonne (t) of peanuts of foreign materials removed by the various extractors ranged from 0.8 kg to 21.3 kg. Aspiration generally doubled the amount of foreign materials removed by the extractors. The primary materials removed by the extractors were dirt, peanut stems, sticks, leaves, small rocks, and some broken or loose shelled peanut meats.