Soybean is a important source of protein and fat in the food and animal feed industries. Moreover, soybean also contains many other compounds, including minerals, which are beneficial for health and reduce the risk of many diseases. This study was conducted at the Czesławice Experimental Farm near Lublin (51°18′23″N, 22°16′02″E) in 2016. The soil on which the experiment was set up belongs to typical Luvisols. It was characterized by high phosphorus and potassium availability as well as very high magnesium availability. The aim of the present study was to determine the effect of cultivation (organic and conventional system) and row spacing (22.5 cm and 35 cm) on the level of minerals in seeds of two soybean varieties: Aldana and Merlin. The study was conducted using a split-plot design, in three replicates. Seeds were sown on May 5, whereas harvest was carried out on September 5, 2016. After seeds were harvested, the content of the following major minerals was determined in them: phosphorus, potassium, magnesium, calcium, molybdenum, manganese, copper and nickel. Variety Aldana seeds were characterized by a significantly higher content of potassium and copper, while in var. Merlin seeds the calcium concentration was higher. The contents of phosphorus, potassium, calcium, copper and nickel were found to be significantly higher in conventional system grown soybean seeds. Seeds of soybean grown at a row spacing of 22.5 cm contained more copper and nickel. Row spacing was not found to significantly affect the macronutrient content in the studied material.