Abstract: The study explores the direct effect of somatostatin (SOM) on some stages of Schistosoma mansoni. Experimentally infected mice with Schistosoma mansoni were investigated following administration of either SOM, artemether (ART) or their combination. Each regimen was administered at 2, 5 and 13 weeks Post-infection (PI) to separate groups. The most presented period of worm reduction was in mice group received SOM at 5 weeks PI (44.28%), 2 weeks PI in ART administration (79.90%) and 2 weeks PI in combined treated group (84.16%). A significant reduction in mature ova (p<0.05) was recorded in ART and combined treated groups at administration 2 weeks PI in addition to an increase in immature and dead ova in all treated groups than controls. The highest percentage reduction of total egg load was recorded in combined treated groups at 2, 5 and 13 weeks PI (88.4, 85.74 and 56.93%), respectively compared to other regimens. The morphological changes of the adult worms in SOM treated groups were elongation, erraticism, agitation and fragility. Male worms showed poorly developed suckers and tuberculations. Both male and female worms showed empty intestines. In ART treated group the male worms showed stunted growth and deformity of suckers. In female worms beside stuntedness, they showed moderately developed ovary, empty intestine and absence of vitelline glands. These observations were highly pronounced in worms recovered from combined treated groups. The study concluded that SOM has an inhibitory role on the parasite of Schistosoma mansoni itself regarding physiological development, worm reduction, egg production and maturity.