A sero-epidemiological survey of Taenia saginata cysticercosis was carried out to determine the prevalence of the infection in cattle presented for slaughter in Belgium. Between November 1997 and June 1998, a total of 1164 serum samples were collected in 20 export abattoirs. Meat inspection was routinely carried out by veterinary inspectors. Serum samples were examined for circulating parasite antigen using a monoclonal antibody-based sandwich enzyme-linked-immunosorbent assay (Ag-ELISA). Thirty six serum samples (3.09%) were found positive in the Ag-ELISA, while by meat inspection on the same animals cysticerci were detected in only three carcasses (0.26%). Sero-prevalence was positively correlated with the age of the animals. The sero-prevalence found in this study was more than 10 times higher than the annual prevalence (0.26%) reported by the Institute for Veterinary Inspection. This study clearly indicates that the classical meat inspection techniques detect only a minor fraction of the carcasses infected with cysticerci.