The work is focused on the proving the presence of residues of inhibiting substances in selected raw materials and foodstuffs of animal origin using a simple screening method. In samples of selected raw materials and foodstuffs of animal origin (meat, milk, eggs) was determined residues of substances inhibiting simple plate agar diffusion test, modified for each species of examined samples by evaluating the inhibition of the growth of test organisms {Bacillus subtilis, Kocuria rhizophila, Geobacillus stearothermophilus, Escherichia coli). Statistical analysis was done using non-parametric tests in Statistica software. After determining the sensitivity of four bacterial strains {Bacillus subtilis BGA CCM 4062, Kocuria rhizophila CCM 552 Goebacillus stearothermophilus var. calidolactis C 935 CCM 5965 and Escherichia coli CCM 7372) to seven commercial antibiotic test disks (gentamicin, chloramphenicol, oxacillin, lincospectin, amoxicillin, erythromicin and ciproflexacilin) were examined for the presence of inhibitory substances in selected samples of meat, milk and eggs