Motility patterns of spermatozoa are an indicator of their fertilizing capacity. Reduced glutathione (GSH) has been reported to induce positive effects on the biological quality of the frozen-thawed spermatozoa. The aim of this study was to investigate the effects of GSH addition to semen extender based on the following kinetic parameters: continuous line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), amplitude of lateral head displacement (ALH), linearity (LIN), straightness (STR), beat cross frequency (BCF), total motility (tMOT) and progressive motility (pMOT), and to appoint them as indicators of its presence. A soybean-based extender was used for dilution of the semen samples, fractioned in two parts, one containing GSH (5 mMol/ml) and second without GSH. The ejaculates (n=48) were collected from two rams (January - May, 2013) which were classified in two groups according to the used extender: Group 1 (with GSH, n=24) and Group 2 (without GSH, n=24), and then frozen in liquid nitrogen on -196°C degrees in a programmable freezer. Assessment of the samples has been performed post-thawing (30 sec. at 37°C) on CASA equipment, acquiring kinetic parameters. Results showed that only VSL and BCF have a statistically significant difference between group1 and group 2 (102.98±15.13 vs. 88.47±20.63, t=2.77, p<0.01 and 32.01±2.68 vs. 89.47±2.92, t=3.13, p<0.01, respectively). The summary of the investigation concludes that none of the kinetic parameters could be appointed as indicators that confer the positive effect of GSH as an additive to soy-bean semen extender.