Schistosomiasis is one of the major communicable diseases of public health and socio-economic importance in the developing world. It is a waterborne disease in which Biomphalaria alexandrina snails are known to be the intermediate molluscan host for Schistosoma mansoni; the causative agent of human intestinal schistosomiasis. Therefore, snail control is one of the corner-stones of schistosomiasis control programmes. Several methods have been used to eliminate snail hosts. One of these methods is chemical molluscicides which have undesirable effect to non-target organisms. Consequently, the search for biologically-derived molluscicides to compliment the use of synthetic one is a top priority. In this concern, the present study is the first evaluation of the molluscicidal potency of Cyanobacteria Phycocyanin (C-PC) as a virtually untapped source. Laboratory assessment of three freshwater Cyanobacterial strains; Anabaena oryzae SOS13, Nostoc muscorum SOS14 and Spirulina platensis SOS13 derived C-Phycocyanin as a bio-control agent against freshwater molluscs; B. alexandrina snails was performed by using a bioassay test. Also, the safety of tested C-PC on non-target organisms (Tilapia fish) was assessed. Results reveal that C-PC extracted from all tested Cyanobacteria strains showed a promising molluscicidal activity (the mortality rate was 100% at 100 µg/ml concentration). Out of the examined strains; A. oryzae SOS13 phycocyanin was found to be the most potent one (LC50 and LC90 were 38.492 and 49.976 µg/ml, respectively). Moreover, C-PC extracts from all tested strains has been found to be safe to Tilapia fish as the survival rate was 100% at the effective molluscicidal concentrations. We can conclude that cyanobacterial phycocyanin extracts are the first promising microbial biopesticides for the control freshwater B. alexandrina snails.