AIM: evaluating the effectiveness of conservative treatment for diverticular disease complicated with first episode of acute diverticulitis. PATIENTS AND METHODS: we investigated the results of the conservative treatment of 68 patients with diverticular disease complicated with first episode of acute diverticulitis. The ages of patients range from 32 to 78. The diagnosis was made based on clinical examination, laboratory tests (markers of inflammation – CRP, faecal calprotectin) and imaging studies (irrigoscopy, colonoscopy, USG, CT, laparoscopy). In 19 of 68 patients (28%) affected segment of the colon was descending colon, in 49 (72%) patients sigmoid colon was effected.RESULTS: all 68 patients received conservative treatment (spasmolytics, antibiotics, probiotics, anti-inflammatory, antibacterial drugs, and diet). Rifaximin was used as antibiotic (daily dose 600-1200 mg). Treatment course lasted for 7 days. We used probiotic (Enterol) to normalize colonic microflora (1 capsule 2 times a day), treatment course lasted for 7-10 days. Long-term outcome of treatment and quality of life of 54 (79,4%) patients were evaluated 2-5 years after a first episode of uncomplicated acute diverculitis. 12 (22,2%) patients underwent medical examinations, in 54 (79,4%) patients we used a questionnaire for assessment. Two scales of MOS 36-Item Short Form Health Survey (MOS SF-36) were evaluated: physical functioning and mental health. Analysis the results of the treatment showed that recurrent episodes of acute diverticulitis did not occur. The analyse of the survey results showed that the mean score of the patients were close to the results of healthy population.CONCLUSION: pathogenetically based multicomponent conservative treatment in the first episode of acute diverticulitis can make a regression and normalize laboratory values.The study showed that no reccurence was reported and the quality of life of the patients was similar to healthy ones after conservative treatment. It confirmes that the conservative treatment is an alternative treatment method for a first episode of uncompliated acute diverticulitis.