The main objectives of this research is to evaluate the molluscicidal activity of the volatile oils of Cymbopogon nervatus and Boswellia papyrifera against the snails Biomphalaria pfeifferi and Bulinus truncatus under laboratory conditions. It is evident from the present results that C. nervatus (LD50 against B. pfeifferi=213.099 ppm; LD50 against B. truncatus=237.33 ppm) and B. papyrifera (LD50 against B. pfeifferi=213.31 ppm; LD50 against B. truncatus=311.05 ppm) essential oils are potential molluscicidal agents. Their toxicity exhibited a dose dependent pattern. The demonstrated bioactivity may be attributed to terpenoid compounds present in these oils. The present study can be considered as the first attempt to evaluate these plants against hosts of Bilharzia. These oils may offer an alternative tool for the control of schistosomiasis in Sudan.