Purified oil and oieo - resin extracts of the Arabian or Somali gum Commiphora molmol (family: Burseraceae) were used as plant molluscicides against the vector snails Biomphalaria alexandrina, Bulinus truncatus and Lymnaea nataiensis. The results indicated that oil extract possesses a higher molluscicidal potency than the oleo-resin. The mortality rate of exposed snails was increased by prolongation of the exposure time. The LC50 values for the oil extract against Lymnaea ncnalertsis were quite lower than (hose utilised with H. alexandrine and B, trunvaius. These values were 5. 4 & 3 ppm. for exposure periods of 24, 48 & 96 hours respectively. Conversely, the oleo - resin extract showed a more pronounced cercaricidal potency than the oil. Total death of cercariae was remarked after 1/4 h of exposure to 10. 5 & 2.5 ppm.