Proteus mirabilis are opportunistic microorganisms which cause serious hospital infections. The resistance of 1038 strains of P. mirabilis to selected antibiotics (lactams, aminoglycosides, fluoroquinolones, nitrofurantoin, cotrimoxazole, tetracycline) was tested by disk diffusion method. The least of P. mirabilis strains were resistant to imipenem and aztreonam. Most of P. mirabilis strains were isolated from urine, wounds and ulcers from patients of departments of urology, dermatology, general surgery and cardiosurgery. P. mirabilis strains were isolated from 4.3% of all positive samples.