This work studied the immunmoprophylactic effect of probiotic yoghurt administration to mice before and after infection with Schistosoma mansoni. Female Swiss albino mice were divided into four groups (G1, G2, G3 and G4), G1 and G3 were fed on the basal diet, G2 and G4 were fed on the basal diet and probiotic yoghurt. After feeding, mice of groups G 3 and G 4 were infected with 100 cercariae of Schistosoma mansoni. Their livers and spleens were removed and their weights were recorded. Plasma were separated and used for the determination of IgM level, aspartate transaminase (AST), alanine transaminase (ALT), lactate dehydrogenase (LDH) and γ-glutamyl transferase (γGT). The results obtained showed that the mean liver and spleen weights were significantly increased in infected mice group (G 3) as compared the with control (G 1). Supplementation of probiotic yoghurt (G 2) decreased the spleen and liver weights to be nearest the control. In addition, probiotic yoghurt was found to display an immunomodulatory effect by stimulating IgM response against soluble worm antigen preparation (SWAP) as compared to the normal control. Also, there was an increase in the IgM level in infected mice fed on probiotic yoghurt as compared to the infected mice not fed on probiotic yoghurt. In addition, the activity of AST, LDH and γGT was significantly increased in the infected group compared with the control. The addition of probiotic yoghurt to a diet in the infected group led to a decrease in the activity of AST, LDH and γGT to be nearest to the control. Hence, we concluded that feeding with probiotic yoghurt resulted in a significant stimulation for IgM response against SWAP before and after infection with Schistosoma mansoni. In addition, the liver and spleen weight were decreased in probiotic yoghurt-infected mice as compared to the non-yoghurt infected mice. Also, the supplementation of yoghurt led to a decrease in the activity of AST, LDH and γGT in the infected mice to be nearest to the control.