The results are presented of a ten-year research programme on the helminth parasites of beef cattle raised in the extensive cerrado region of central-east Brazil. The most important helminths are Cooperia spp., Haemonchus spp. (80% H. similis), Trichostrongylus spp. and Oesophagostomum radiatum. Both production and infection are dominated by the alternation of rainy and dry seasons. Attempts to develop and implement control measures and their limitations are discussed.