Control of Schistosoma mansoni transmission in a town in northern Ethiopia was attempted using the natural product, endod (Phytolacca dodecandra), and its use compared with niclosamide. Within a five year period prevalence was reduced from 61.5 to 36.4% in the area where endod was used. Most of this decline was accounted for by the reduction in prevalence among 1-6 year old subjects. The practical use of endod as a molluscicide was demonstrated to have a performance which compared favourably with the commercial product, and although more expensive than niclosamide still at minimal annual cost (US + 0.06 per capita).