In the years 2002–2003 at the Experiment Station in Wierzchucinek belonging to the Technical-Agricultural University a two-treatments field experiment with milk thistle was carried out on gray podsolic soil. The influence of three NPK doses (180, 260 and 325 kg ha-1) and microelement fertilizer Basfoliar 36 Ex applied on the leaves on the yield and chemical composition of fruits were tested. Under the influence of the dose 180 kg NPK ha-1 the average yield of fruit 1,86 t ha-1 was obtained. A statistically higher yield was obtained at the dose 260 kg NPK ha-1 – 2.19 t ha-1. It was confirmed that the increase of the level of NPK fertilization caused the decrease of potassium content and it has no effect on the content of nitrogen, phosphorus and oil. The dose of Basfoliar 36 Ex caused a statistical increase of the yield of fruits and increase of the content of potassium, phosphorus and oil.