The study involved 180 Nigerian butchers and 180 traders (controls) selected by multistage stratified sampling who had their sera assayed for HBsAg (hepatitis B surface antigen) by enzyme-linked immunosorbent assay method. The butchers and the controls had an HBsAg sero-prevalence rate of 9.4% and 3.3%, respectively. Various risky practices were more common among the butchers but their hepatitis B antigenaemia was not related to the duration of their occupational exposure. The study shows that the butchers constitute a high risk occupation for hepatitis B viral infection.