OBJECTIVES: The cost analysis of ten schemes antibiotic therapy (AT) in patients with acute peritonitis was conducted. These schemes are recommended by the Clinical Protocol of acute peritonitis treatment (MHO of Ukraine, order ¹297, 02.04.2010) for use in practice. METHODS: The schemes of antibacterial therapy are: I – ertapenem (1,0 gr intravenously (iv.) 1 time/day); II – cefotaxim (1,0 gr im. 3 times/day and metronidazol 100 ml (sol. 0,5%) iv. 2 times/day); III – amoxicillin clavulanate (1,2 gr 3 times/day); IV – moxifloxacin (400 mg 1 time/day); V – levofloxacin (500 mg iv. 1 time/day and metronidazol 100 ml (sol.0,5%) iv. 2 times/day); VI – cefepim (2,0 gr iv. 2 times/day and metronidazol 100 ml (sol.0,5%) iv. 2 times/day; VII – cefoperazone + sulbactam (2,0 gr 3 times/day); VIII – meropenem (500 mg iv. 4 times/day); IX – imipenem + cilastatin (500 mg/500 mg iv. 4 times/day); X – ciprofloxacin 400 mg iv. and metronidazol 100 ml (sol.0,5%) iv. 2 times/day. Three variants for each scheme were calculated: the schemes with original drugs, the schemes with generics and the schemes with ukrainian generics. Doses and duration of AT were calculated in accordance with the Clinical Protocol of acute peritonitis treatment. RESULTS: The costs range of treating one patient with acute peritonitis with original drugs is 3891 UAN (scheme I) - 7994 UAN (scheme VI). The costs range with generics of ukrainian production is 1924 UAN (scheme V) - 5413 UAN (scheme VIII) (1 EUR = 11,65 UAN). CONCLUSIONS: The costs of treatment schemes for patients with acute peritonitis with use of less expensive generic drugs are not always cheaper than the costs of original drugs using. The optimal schemes for treatment of patients with acute peritonitis were selected.