Biologically active agents show several biomedical applications. Non-chitosan loaded diethyldithiocarbamate (DDC) was previously found to have anti-schistosomal activity. The present work aimed to prepare DDC-Chitosan-Na-nanoparticles (DDC-Chitosan-Na-NPs), and to investigate it's in vitro anti-schistosomal activity with slow release approach and as well as its mortality % against both concentrations and exposure time. NPs were prepared by suspension cross linking method, in which 0.16 g chitosan were dissolved in 16 ml 2% acetic acid solution (ratio 1% wt/v.). Then after, 0.1g DDC-Na salt was added to the chitosan solution and 3.2 ml of glutaraldehyde as a cross linking agent was added into the mixture dropwise. NPs were washed several times with ethanol 70%, dried under vacuum, prepared for chemical characterization and biological assessment. Our data showed that the slow release of DDC-chitosan-NPs resulted in mortality effects on Schistosomal worms in vitro when applied with small dose for longer time. These data compared to those of prazoquantil (PZQ) as a reference drug showed that administration of DDC loaded with chitosan-NPs was more effective on the mortality of Schistosoma worms. In conclusion, DDC-Chitosan-NPs have lethal effects on S. mansoni worms in vitro by a unique mode of action in a way of concentration and exposure time dependent. Also we recommend that the development of DDC as a local, cheaper and more effective agent against S. mansoni worms.