Tsetse, caught in biconical traps near Bouaflé, Ivory Coast in 1980-81, were examined for trypanosome infections. In a sample of 1138 non teneral Glossina palpalis s.l. there were infection rates of 12.2% (all infections) and 5.3% (mature infections). Female flies had a significantly higher infection rate than males. In G. palpalis only 3 (0.26%) salivary gland infections were detected, 62.3% of the mature infections were T. vivax-like and 71.4% of all infections were restricted to the midgut. The infection rate in forest/plantation caught G. palpalis was twice that of village caught flies. The infection rate increased with fly age and is correlated in female flies. In smaller samples of G.p. pallicera and G. fusca group flies the trypanosome infection rates were 37% and 46% respectively. In both these groups of flies 64.7% of infections were mature and were predominantly T. vivax-like and in females.