Six Nigerian species of F a gar a were examined for the presence of acids in the ether fraction of the water extracts (antisickling activity fraction1) of their morphological parts. All were found to contain acids. The total acid (calculated as p–OH–benzoic acid) in these morphological parts were quantitatively estimated using a new colorimetric procedure which showed that the acid content varied from species to species and also among the morphological parts of each species. The leaves were found to contain the most acid in the antisickling fraction. The significance of these findings in relation to the antisickling activity reported in the root of a Fa gara species is discussed.