Objective: This study aimed to investigate the effect of adding cysteine to an Low Density Lipoprotein (LDL)-based extender on some quality parameters of goat sperm after freezing. Method: This study was conducted in a completely randomized design with four treatments, including: egg yolk-based extender without cysteine (EY), LDL-based extender containing zero (LDL-C0), five (LDL-C5), and 10 (LDL-C10) mM cysteine, and six replicates. Semen samples after dilution with the aforementioned extenders, were frozen. Results: After thawing, total and progressive motility, sperm plasma membrane integrity, functionality, and sperm morphology were evaluated. Total motility was higher in LDL-C5 compared to EY and LDL-C10 (P <0.05). Progressive motility in all treatments using LDL-based extender was significantly higher than EY. Other motility parameters were higher in LDL-C5 compared to EY (P <0.05). However, no significant differences were observed between the LDL-C0, LDL-C5, and LDL-C10, except for the VSL, which was significantly lower in LDL-C0 compared to LDL-C5 (P <0.05). Sperm plasma membrane integrity, functionality, and sperm morphology were higher in all treatments using LDL-based extender compared to EY (P <0.05), with the highest values observed in LDL-C5. Conclusions: Overall, the results showed that adding 5 mM cysteine to the LDL-based extender can improve some quality parameters of goat sperm and using semen from this group may enhance both in vitro and in vivo fertility.