humans and animals. It causes severe and chronic diseases in HIV positive people and neonates. As yet no effective treatment has been found for it. The aim of this study was to evaluate the therapeutic effects of blue berry cherry, garlic and mixture of them on the Cryptosporidium parvum oocysts in HANK medium.Material and methods: Different concentrations of blue berry cherry extract, garlic tablets and mixture of them, with dilutions of %100, %50, %25 and %12.5, were prepared and sterilized by filter 0.22. The oocysts were separated from the stool of young calves suffering from diarrhea and were concentrated by use of sucrose and Shyter methods. 100A of the concentrate containing 2x106 oocysts and 900l of the above mentioned dilutions (blue berry cherry extract, garlic tablets and mixture of them) were poured into the Ependrof vials (pipes) and kept into an incubator at 370C for 24 to 48 hours (tests were performed in triplicates).Results: The results showed that all concentrations were effective in reducing Cryptosporidium parvum oocysts, but 1/100 garlic concentration, was more effective than blue berry cherry at the same concentration (P<0.001). The mixture of them had the highest effect on reducing Cryptosporidium Parvum oocysts compared with those of blue berry cherry or extract of garlic tablets (P<0.001). Blue berry cherry, garlic and mixture of them are effective in reducing Cryptosporidium oocysts.Conclusion: Since chemical compounds have side effects, use of blue berry cherry, garlic and mixture of them even in very low doses, can reduce the number of oocysts of this parasite, which is probably due to presence of allicin in garlic and polyphenolic compounds in blue berry cherry. Therefore, they can be used in children, elderly and those with immune system defects.