The quality of soybean seeds is influenced by the amount of nutrients that are available for the germination and initial development of the seedlings. Thus, the aim of this research was to evaluate the influence of the nutritional content of the seeds and mineral supplementation via seed treatment on physiological quality, enzymatic activity and initial development of soybean seedlings. We assessed soybean seeds from two lots with low and high nutritional content, submitted or not to mineral supplementation via seed treatment. The physiological quality of seeds was assessed by the germination test and first germination count. The initial development of seedlings was evaluated by the tests of length and root system volume, shoot length, and cotyledons, roots and shoot dry matter. It was also determined the activity of α-amylase in cotyledons, acid phosphatase (APase) and guaiacol peroxidase (POD) in the roots and shoot. Mineral supplementation via seed treatment positively influenced the physiological quality and development of seedlings, and the activity of α-amylase in the cotyledons, POD and APase enzymes in the shoot from the low nutrient lot. Low nutrient seeds have characteristics of soybean seedling production similar to those of high nutrient content by using mineral supplementation via seeds.