Bluetongue virus (BTV) group antibodies are widely distributed in Costa Rica and Northern Colombia; prevalence is highest at lowest altitudes. Clinical evidence of bluetongue (BT) infection in cattle is not seen. Evidence exists of the circulation of BTV serotypes 6 and 14 in Costa Rica and BTV serotype 12, 14 and 17 in Northern Colombia in the period 1981-1983. Culicoides insignis is implicated as a probable vector in Colombia.