Background/Aim. The most common cause of acute dental infections are oral streptococci and anaerobe bacteria. Acute dentoalveolar infections are usually treated surgically in combination with antibiotics. Empirical therapy in such infections usually requires the use of penicillin-based antibiotics. The aim of this study was to investigate the clinical efficiency of amoxicillin and cefalexin in the empirical treatment of acute odontogenic abscess and to assess the antimicrobial susceptibility of the isolated bacteria in early phases of its development. Methods. This study included 90 patients with acute odontogenic abscess who received surgical treatment (extraction of a teeth and/or abscess incision) and were divided into three groups: two surgicalantibiotic groups (amoxicillin, cefalexin) and the surgical group. In order to evaluate the effects of the applied therapy following clinical symptoms were monitored: inflammatory swelling, trismus, regional lymphadentytis and febrility. In all the patients before the beginning of antibiotic treatment suppuration was suched out of the abscess and antibiotic susceptibility of isolated bacteria was tested by using the disk diffusion method. Results. The infection signs and symptoms lasted on the average 4.47 days, 4.67 days, and 6.17 days in the amoxicillin, cefalexin, and surgically only treated group, respectively. A total of 111 bacterial strains were isolated from 90 patients. Mostly, the bacteria were Gram-positive facultative anaerobs (81.1%). The most common bacteria isolated were Viridans streptococci (68/111). Antibiotic susceptibility of isolated bacteria to amoxicillin was 76.6% and cefalexin 89.2%. Conclusion. Empirical, peroral use of amoxicillin or cefalexin after surgical treatment in early phase of development of dentoalveolar abscess significantly reduced the time of clinical symptoms duration in the acute odontogenic infections in comparison to surgical treatment only. Bacterial strains isolated in early stages of dentoalveolar abscess showed high sensitivity to amoxicillin and cefalexin.