The study was carried out at the Agricultural Experimental Station in Felin affiliated with the University of Life Science in Lublin. The experimental material consisted of 5-year-old plants of cv. Bluecrop highbush blueberry growing in a mixture of sphagnum peat, sand and finely ground pine bark (v/v: 2:1:1) in 35 dm³ containers. Two factors were taken into account in the experiment: A – form of nitrogen: 1) ammonium, 2) nitrate, 3) amide; B – fertilization level corresponding to the content in the substrate: 0, 100, 200, 400 mg N dm^-3. The following fertilizers were used: ammonium sulphate (21% N-NH₄, 24% S), magnesium nitrate (11% N-NO₃, 9.5% Mg), urea (46% N), monopotassium phosphate (22.3% P, 28.2% K), potassium sulphate (44.8% K, 17.0% S) and magnesium sulphate (9.5% Mg, 12.7% S). In leaves and fruits, total nitrogen was determined using the Kjeldahl method on a Foss Tecator apparatus, phosphorus was measured colorimetrically with ammonium vanadomolybdate (Thermo Evolution 300), while potassium, magnesium and calcium, and also manganese, iron, zinc and copper in leaves were determined with the ASA method (Perkin-Elmer, AAnalyst 300). The study found that the N-form had no effect on the content of nitrogen and phosphorus in leaves. The N-form had a significant effect on the content of potassium, magnesium, and calcium. The tested fertilization levels influenced significantly the concentration of nitrogen, phosphorus, and magnesium, whose values increased in direct proportion to the mineral fertilizer doses, while the opposite relationship was observed for Ca. The macronutrient contents in leaves (except for N in the control) corresponded to optimal values for the limit values, indicating proper nutrition of the highbush blueberries in this experiment. The highbush blueberry leaves were characterized by optimal contents of Mn, Fe, Zn, and Cu, with the exception of Fe and Cu in the control. The N form significantly influenced the content of Mn, Zn, and Cu, in addition to Fe.