Abstract Introduction Clostridium difficile is the leading cause of nosocomial and antibiotic-associated diarrhea in adults, and its incidence has substantially risen over the last few years. The prevalence of this infection in children is difficult to assess due to the high rates of colonization in this setting. Material and methods A one-year retrospective study was conducted on children under 15 years admitted to hospital with acute diarrhea. Epidemiological, clinical, laboratory findings and outcome of children with Clostridium difficile infection (CDI) were compared to other causes of diarrhea. Risk factors for CDI were identified by multivariate analysis. Results Two hundred and fifty children with acute diarrhea were identified. A microbiological pathogen was identified in 79 (45.4%) of 174 patients who underwent complete testing: 19 CDI (25.6%, 13 of which were enterotoxin-producing), 21 other bacteria (28.6%), and 34 viruses (45.8%; rotavirus n=31; adenovirus n=3). The estimated incidence of CDI was 3 cases/1,000 admissions, with 68.4% of them occurring in children younger than 2 years. Overall, 15.8% were community-acquired. Compared to other causes of diarrhea, CDI was associated with comorbidity (P<.0001), recent contact with the health-care system (P<.0001) or intensive care unit stay (P=.003) and exposure to antibiotics in the previous month (P<.0001). The clinical course of children with CDI was less symptomatic. There were no clinical differences between Clostridium difficile toxin-producers and non-toxin producers. Comorbidity was identified as the main risk factor associated with CDI (OR 40.02, 95% CI 6.84-232.32; P<.0001). Conclusions The isolation of Clostridium difficile is common in hospitalized children with diarrhea in our setting. CDI is more frequent in children with comorbidity and recent contact with the health-care system, presenting a mostly oligosymptomatic clinical course. Further studies are needed to understand the epidemiology of this infection in pediatrics, especially the percentage of asymptomatic carriers.