Probiotic yeast, Cryptococcus humicola M5-2 strain, which has high cholesterol assimilation feature and isolated from traditionally produced cheese, was investigated in vivo. This study was conducted to determine cholesterol assimilation ability of C. humicola M5-2 in vivo and specify the effect of the strain on serum total cholesterol, HDL/LDL cholesterol and triglycerides levels in rats fed on cholesterol-enriched diet. C. humicola had the ability to assimilate cholesterol at the rate of 73.33% in media. The strain was used with two different concentrations in animal feed (high and low doses containing 2% and 0.1% lyophilized strains, respectively). When the treatment groups were compared, low dose feeding group had the positive results in terms of testing values. According to the results of serum analysis, triglyceride and total cholesterol level were decreased by 25% and 1.34% respectively. Especially, decreasing the percentage rate of triglyceride has not obtained in other in vivo studies. It is thought that health promoting effect will be possible when the obtained isolate is consumed with fermented foods.