Eggplant fruits are known for being low in calories but rich in minerals, which is good for human health. They are rich in potassium, whose content ranges from 200 to 600 mg K⋅100 g-1 of fresh mass, depending on a cultivar. Eggplant fruits are also a source of magnesium, calcium and iron. Research on the agro-techniques of eggplant culture in a plastic tunnel has implicated that, on account of a very intensive growth of the plant, both plant pruning and training have a decisive influence on the final amount of fresh mass. Since we lack information concerning the fertilization recommendation for growing eggplants under a plastic tunnel, a study has been undertaken to specify such nutritional needs of this vegetable. The aim of this work has been to determine the influence of nitrogen forms and plant training methods on the content of nitrogen, phosphorus, potassium, calcium and magnesium in eggplant fruits. The experiment on cv. Epic F1 eggplant was carried out in years 2004-2005, with eggplants growing in an unheated plastic tunnel. The eggplants were cultivated in cylinder plastic wraps of 10 dm3 volume, in peat. The experiment was carried out in two stages, in a completely random design, with each stage examining different factors. The following factors were examined: I – nitrogen forms: NH4 + (ammonium sulphate – (NH4)2SO4 (20,5% N); NO3 - (calcium nitrate – Ca(NO3)2 (15,5% N); NH2 (urea – CO(NH2)2 (46% N), II – plant training method: natural form of the plant, 3 shoots. Nitrogen was used in the amount of 10 g N⋅plant-1. Samples of fruits used for further laboratory tests were collected in the 2nd decade of August, in the middle of fructification. The fruits were harvested at the marketable stage. N-total, P, K, Ca, Mg were determined in the fruits. The results were elaborated statistically using analysis of variance. Generally, considerably higher content of nitrogen was determined in eggplant fruits fertilised with the N ammonium form; also the content of potassium and magnesium was much higher in comparison to the other nitrogen forms examined. Moreover, significant influence of the plant pruning method on the content of the elements was found, independently of the applied nitrogen fertilization.