The purpose of this study was to verify the efficiency of methods of pre-conditioning and concentrations of tetrazolium solution in the evaluation of physiological quality of Stizolobium aterrimum seeds. Commercial seeds have passed through the process of accelerated aging for composing lots of 0, 24, 48, 96 and 144 hours, and were submitted to the pre-conditioning: 1) Scarification with sandpaper number 100 and immersion in water at room temperature for 18 hours, 2) Immersion in water at 95°C and maintained in the same water outside the heating at 25°C for 18 hours. After preconditioning, the seed coats were removed and immersed in embryos tetrazolium salt at 0.25%, 0.5% and 1% for 150 minutes and maintained in the dark at 25°C for color development. To compare the results obtained in the tetrazolium test, we performed germination test, first counting and germination speed index. The method of scarification with sandpaper and later soaked in water for 18 hours at 25°C, the most efficient way in preconditioning of seeds of Stizolobium aterrimum and concentration of 1.0% tetrazolium solution for 150 minutes at 25°C, allows evaluating the quality of seed lots from this species.