Objective: Gastrointestinal infections are one of the major health problems in developing countries. The present study aims to estimate the prevalence of gastrointestinal infections in Ouagadougou, the capital of Burkina Faso. Methods: A door-to-door survey of selected residents in Ouagadougou city was conducted. Of the Ouagadougou's 30 districts, nine most populated ones were selected to the study. The residents of these districts have middle incomes as those of the secondary cite of Burkina Faso. Results: The overall prevalence of gastrointestinal infections in the 30 days prior to the interview was 77/491 (15.7%): among children 44/223 (19.7%) and among adults 33/268 (12.3%). Diarrhea and abdominal pain were the most common symptoms among 33 adult cases while diarrhea and vomiting were the most common among children. None of the cases were hospitalized and a stool sample was taken in three of 77 cases. Medication for gastrointestinal infections was received by 55% percent of adults and 77% of children. Conclusions: Our results shown that antibiotics with and without prescription were the most common medicine used. Washing hands before meals and boiling milk before drinking had a protective effect against gastrointestinal infections.