Introduction: Effects of prior sperm preperation methods on frozen-thawed sperm samples was aimed to be compared by flow cytometry. Ejeculates obtained from twelve healthy volunteers which were divided into two: either washed by density gradient centrifuge method or frozen as raw samples. After thawing at room temperature, samples were double washed and analysed by flow cytometry. Percentage of live, apoptotic and death cells were recorded and compared by paired t test. No significant difference was found between death cell rates of the pre-freezing prepared and unprepared samples on flow cytometry (n=12, t=-2.012, p=0.072). Percentages of live cells was higher (t=3.744, p=0.004) and apoptotic cells was lower (t=-3.860, p=0.003) in the pre-freezing prepered samples compared to raw frozen samples. It was concluded that, sperm preperation by density gradient method prior to freze-thaw procedure improved the parameters of sperm samples. This method would be especially effective in oligospermic patients by increasing the concentration of healthy sperm cells and inorder to get rid of the agents that increase the oxidative stres. However, in healthy male, freezing of the raw sperm samples could be choosen as an easier and cheaper method.