This study was undertaken to determine the viability of cototn seed during storage under controlled (35% R. H.) and uncontrolled conditions. Seed germination and two methods of vigor analysis accelerated aging and seed irradiation - were used for evaluation of seed behavior, during eight months. The results showed that uncontrolled conditions were more detrimental to seed viability. Accelerated aging was found to be an effective method to determine the progress of seed deterioration during storage. Seed irradiation results may be correlated with accelerated aging, depending on the dosage used.