Background and Objective: Oxidative stress is one of mechanisms involved in apoptosis of motor neurons during neurodegenerative diseases and spinal cord injuries. Despite of extensive researches, there is no universally accepted treatment for these diseases. Therefore, the aim of this study was to investigate if quercetin, as a powerful antioxidant, with reducing oxidative stress is able to delay the apoptosis of motor neurons in cultured spinal cord slices. Materials and Methods: Thoracic region of spinal cord of adult mouse was cut into 500 μm slices. The slices were then divided to three groups: 1. Freshly prepared slices (0 hour); 2. Control slices; 3. Slices treated with quercetin (100 μM). The control and the treated slices were cultured in a medium for 6 hours in a CO2 incubator. Morphological features of apoptosis in the motor neurons were studied using fluorescent staining. The amount of malondialdehyde (MDA) and Ferric reducing antioxidant power (FRAP) were assessed for evaluating lipid peroxidation and total antioxidant power respectively. Results: After 6 hours, the motor neurons displayed morphological features of apoptosis compared to the control group. At this time point, quercetin not only delayed morphological features of apoptosis in the motor neurons but also significantly compensate the changes MDA and FRAP in the cultured slices. Conclusion: Since quercetin was able to reduce lipid peroxidation, increase the total antioxidant power and delay the morphological features of apoptosis, it is possible that oxidative stress is responsible for apoptosis of motor neurons.