Background. In spite of advances of knowledge in the area of controlling hospital infections SSI remains main cause of morbidity and mortality among patients undergoing surgical treatment. In the current paper, results of epidemiological and microbiological analyses of SSIs are summarized, regarding patients, subject to surgical treatments in 2 orthopedic units. In 2005, 218 surgical treatments were carried out – identified 14 SSIs. Infections were classified, according to definitions and criteria of the NNIS. Material and methods. A SSI incidence of 7,0 and 4,3% was found. Superficial infections constituted a majority of 75%. Post-discharge recording covered 42% of cases only in 1st unit. A median of duration of patients’ stay in the 1st unit 17 days an the 2nd 25 days. Among etiological factors of all the clinical forms of the SSI, a dominant part was consisted of gram-positive positive cocci (65.4%). The incidence rate in 2 polish units were significant higher then in Germen population (KISS). Prevalence of G(+) bacteria was found among isolated bacterial flora, although numerous occurrences of G(-) cocci were also identified. The obtained data confirm the necessity of continued close cooperation of the infection control team with the microbiological laboratory. The analysis of data pertaining to leading SSI etiological factors as well as their medication susceptibility should enable elaboration of own standards for surgical infection prophylaxis and empirical therapy to be used in the ward being a subject of study.