Rotavirus infection (RVI) plays a significant role in pediatric pathology and occupies a dominant position in the structure of acute intestinal infections. Objective: to conduct a comparative assessment of the efficacy of multistrain and single-strain probiotics in the complex treatment of rotavirus infection in children. Material and methods. A retrospective two-center study was conducted involving 294 children aged 1 to 7 years with confirmed RVI: 112 patients received inpatient treatment (groups C1 and C2), and 182 were treated on an outpatient basis (groups A1 and A2). In addition to standard therapy (rehydration, diet, enterosorbents), patients in groups C1 and A1 received a multistrain probiotic (Bac-Set), while patients in groups C2 and A2 received a single-strain probiotic (Saccharomyces boulardii). The duration and severity of clinical symptoms (diarrhea, vomiting, fever, abdominal pain) as well as the condition of intestinal microbiota were evaluated. Statistical analysis was performed using Statistica for Windows, v.10 (StatSoft, USA). Normality of distribution of quantitative variables was assessed using the Shapiro–Wilk test (for n