Resumo. Due to absence of information about the methodology for the evaluation of the physiological quality of seeds of medicinal arboreal species seeds, the aim of the present work was to determine the most efficient method to overcome the seed coat dormancy in seeds of Sideroxylon obtusifolium (Roem.& Schult.) T.D.Penn.. Besides the intact seeds, the ones which had not been submitted to any treatment, the following pre-germinating methods were used: chemical scarification: the seeds were immersed in pure sulfuric acid for 10, 20, 30, 40, 50 and 60 minutes at the environment temperature (27ºC ± 1ºC); mechanical scarification: the seeds were rubbed manually in sandpaper number 50, in the opposite side of micropyle, without and with soaking for 24 or 48 hours; thermal scarification: immersion in water at 100ºC for 15 or 30 seconds; immersion in water to 80ºC until cooling. The effects of treatments were evaluated through tests of germination and vigor. There were significant differences among the treatments for all the evaluated parameters (percentage and speed of germination, length and dry weight of shoot and root), and the most evident cause of dormancy was the coat impermeability, which efficiency was overcame by the immersion of seeds in pure sulfuric acid for 30 minutes.