En 1680-6433 2008-2177 Upstream; a novel method for separating human motile sperms - Background: Sperm preparation is a fundamental step in ART and attempt for developing new methods to be continued. Objective: To evaluate the efficacy of upstream method for separation of human spermatozoa and its effects on sperm parameters including: motility morphology and concentration. Materials and Methods: Semen samples from 17 men who referred to infertility clinic for evaluating their infertility problems were collected. Semen was placed in floor of the upper container of device and then media was gently placed on the upper semen portion. During the procedure semen flowed from upper container and <font><font>drop</font></font>ped in lower container. When semen flowed the non-motile sperms cells debris and seminal plasma enter the lower container while only motile sperms separated by swimming upstream and go to the upper part of the medium. Finally all of the semen flowed from the upper container to the lower one and merely the medium remained which contained motile normal sperms. Results: With application of upstream method the recovered spermatozoa showed significant improvement with motility and normal morphology. The data showed that mean sperm motility increased from 39% to 90% (p - Sperm preparation Swim up Seminal plasma Sperm separation Upstream. 141 144 Farhang Abed abedfar@yahoo.com No