- This research was performed with the aim to evaluate the quality of soybean seeds utilizing temperatures below and above the ideal. Two assays were conducted in laboratory utilizing ten soybean genotypes (Doko, IAC 11, Savana, CRI, CR3, Criatalina, IAC 8, UFV 15, FT 11 e Garimpo), harvested in two different dates, one when physiological maturity was reached and the other 30 days overdue harvest maturity. The assays were in a randomized complete block with four replications, and the treatments arranged in a fatorial design (10 x 2), in a combination of ten soybean genotypes and two harvest dates. Germination was evaluated at temperatures below and above the ideal. Seeds were placed on germination on paper rolls at the temperature of 18°C (64,4°F) and 32°C (89,6°F), respectively. To evaluate storage conditions, the seeds were stored in a cold chamber for twenty months. According to the results presented and discussed in this research, it was concluded that: a) when the seeds were harvested at the physiological maturity, all genotypes behaved in a similar way, maintaining a high germination percentage at the temperature below the ideal; as after the storage in cold chamber for twenty months. However, when the harvest was delayed, the same was not observed; b) the genotype Doko exceled as of great quality of the seed when harvested at physiological maturity. The CR1 presented bad quality in both dates. Concerning to the harvest delay, the genotype IAC-11 and Cristalina presented good tolerance, but a FT 11 presented low tolerance; c) when germination was achieved in temperature above the ideal, even for the seeds harvested at physiological maturity, the genotypes had different behaviours, deserving attention to Garimpo and Doko among the least sensitive, and CR3 as the most sensitive to high temperature; d) the dry matter weight per seedling was not an adequated method to evaluate the physiological quality of the seed, but germination at the temperature below the ideal was efficient.