Abstract: In order to ascertain the correlation between schistosomicidal effect and the concentration of solution of potassium antimonyl tartrate,investigation was made in experimentally infected rabbits treated intravenously with the same dosage of potassium antimonyl tartrate in 3 different concentrations.The average number of worms recovered from groups of animals receiving 0.5%,1% and 2% solutions was 26.9,30.3 and 41.1 respectively while that from untreated animals was 104.0.It seems that the curative effect of potassium antimonyl tartrate is inversely related to the concentration of solution used.