Background: Semen preparation techniques were developed to separate motile sperm that are morphologically normal from seminal plasma to optimize successful assisted reproductive technology cycles which seem to be the most effective options in cases of a male factor infertility. Objective: The objective of the present study was to compare between outcomes of two sperm preparation techniques for asthenozoospermic patients includes:1-Centrifugation swim up technique.2-Glass wool filtration technique. Subjects, Materials and Methods: Fifty three infertile males were participated in this study during their attendance to the Infertility Clinic at High Institute for Infertility Diagnosis and Assisted Reproductive Technologies; Al-Nahrain University. Semen samples were collected and SFA was done according to WHO (2010 and 1999). Each semen sample was divided into two aliquots. The first one prepared using centrifugation swim up technique, while the other one prepared using glass wool filtration technique then sperm parameters were assessed for both techniques and the results were statistically analyzed. Results: After in vitro sperm activation using both techniques, there was significant reduction (P<0.05) in the sperm concentration, significant improvement (P<0.05) in the percentages of sperm motility and morphologically normal sperm when compared to pre-activation. Present study appeared that the glass wool filtration technique resulted in significantly (P<0.05) better results for sperm concentration and total number of progressive motile sperm than the swim-up technique. The present study proved that there was significant (P<0.05) improvement in sperm parameters (increment for sperm motility (%), progressive sperm motility (%), total number of progressive motile sperm and normal sperm morphology (%), while reduction for round cell count and sperm agglutination percent) for all cases using glass wool filtration techniques. In contrast, there was failure of sperm activation for 10 cases using centrifugation swim up technique. Conclusions: From results of the present study, the sperm parameters outcomes using glass wool filtration technique was superior to the outcomes of centrifugation swim up technique when prepare semen of asthenozoospermic patients.