Objective: The main objective of this work is to study the broad spectrum effects of Nitazoxanide on Echinococcus granulosus protoscoleces as an example of Helminthes and Blastocystis forms as an example of protozoa in vitro compared to the standard drugs for both parasites. Methods: Hydatid protoscoleces and Blastocysis were cultivated each on its specific medium. The Culture tubes were divided into three groups to which; Nitazoxanide, Albendazole and combined both drugs were added in case of hydatid. While for Blastocystis, the culture tubes were divided into three groups to which; Nitazoxanide, Metronidazole and combined both drugs were added. These culture tubes were compared with that of the control culture with no added drugs. Viability of both parasites was assessed before and after adding the drugs by monitoring movement of suckers and rostellum and the use of Trypan blue exclusion test in case of hydatid, while for Blastocystis, viability assessment was done by Neutral red stain. Further confirmation of viability was done by subjecting samples to electron microscopic study for both parasites.Conclusion: For hydatid, there was direct proportional relationship between number of dead protoscoleces and tested Nitazoxanide concentration together with the exposure time. The lethal dose of Nitazoxanide which killed 50% of protoscoleces was 10µg/ml at 24 hours i.e. LD50 of Nitazoxanide was10µg/ml at 24 hours while its Lethal dose which killed 90% of protoscoleces was15µg/ml at 24 hours i.e.LD90 was 15µg/ml at 24 hours. LD50 of Albendazole was 30µg/ml at 6 hours while its LD90 was 30µg/ml at 48 hours. Combined both drugs demonstrated variable effect against hydatid. 80% of control culture protoscoleces remained viable till the end of exposure time. For Blastocystis, LD50 of Nitazoxanide was 2µg/ml at 48 hours in some cultures. LD90 of the drug was 10µg/ml at 48 hours in one of the cultures. Metronidazole produced variable effect against Blastocystis (40-76% deaths) at a concentration of 200µg/ml after 48 hours in all cultures. Combined both drugs showed variable effect against Blastocystis. Electron microscopic study showed structural and morphological changes in drug treated cultures of both parasites.