S. saponaria L. is a Brazilian native arboreal species, with relevant ecological importance in the recovery of degraded and marginal areas. The objectives of the present study were to characterize morphometrically Sapindus saponaria L. seeds, to extract and to quantify oil content, establish the percent composition of fatty acids; to describe their different post-seminal stages; to describe the different post-seminal stages, as well as to evaluate the germinative performance of the seeds as a function of different treatments to overcome dormancy. Seeds were evaluated as to water content and biometric length and width. The extraction and quantification of the seed oil was obtained by the solvent extraction method using the Soxhlet extractor system. Regarding the post-seminal development, some processes triggered during growth and development of the seedlings were evaluated. The treatments for dormancy overcoming were: mechanical scarification, chemical scarification with sulfuric acid for 5, 10, 20, 30 and 40 minutes, immersion in hot water (80 ºC) until reaching room temperature, immersion in distilled water at room temperature for 24 hours and intact seeds (control). The seeds were evaluated for germination, velocity, medium time, synchrony and germination uncertainty. The design was a completely randomized design with four replicates of 25 seeds per treatment. The seeds present on average 10.3 mm in length and 10.2 mm in width with hygene-cryptocoledonar germination. The oil content found in the seeds was 7.25%, most of which was composed of unsaturated fatty acids (78.9%). The highest values of germination occur when the seeds are immersed in sulfuric acid for 30 minutes.