Анотация: The aim of the present investigation is to evaluate the presence of myнcotoxins Zearalenon and Deoxinivalenol as natural contaminators of the basic cereal components of combined feed in this country - maize, wheat, barley and oats.. - A total of 281 samples, including maize 104, wheat 103, barley 39 and oats 35, stock cereals from 2003 - 2005 crops had been evaluated.. - More favorable substrates for their accumulation had been maize, wheat and barley, while for oats the presence was established only in some of investigated years.. - The average concentrations of Zearalenon for maize vary between 398 and 838 mg/kg, for wheat between 450 and 884 mg/kg, for barley between 320 and 378 mg/kg, for oats between 250 and 350 mg/kg.. - The average concentrations of Deoxinivalenol for maize vary between 237 and 372 mg/kg, for wheat between 336 and 678 mg/kg, for barley between 250 and 333 mg/kg, and for oats 250 mg/kg