IntroductionThere is a high prevalence of obesity among the Saudi population. Anemia due to iron deficiency or an inflammatory state is often associated with obesity. Multiple nutritional deficiencies are associated with bariatric surgeries, with anemia being one of the commonest causes.AimThis study aimed to evaluate the prevalence of anemia after bariatric surgery among patients in the Qassim Region, Saudi Arabia.Patients and methodsThis retrospective cohort study was conducted at King Fahad Specialist Hospital Al-Qassim (Buraydah), Saudi Arabia. We reviewed data from patients' records who underwent bariatric surgeries from January 2018 to January 2021. By using a structured data collection form, we collected data such as demographic variables, surgery perioperative-related data, postoperative complications and interventions, type of transfusion required after surgery, postoperative medications and/or supplements and duration, and blood count indices.ResultsOf the 520 patients who underwent bariatric surgery, 61% were females, and 31.7% were aged between 26 to 35 years old. The most prominent type of bariatric surgery was sleeve gastrectomy (97.1%). The prevalence of anemia among patients who underwent bariatric surgery was 28.1%. Independent risk factors for anemia were female gender, microcytic red blood cells, and low normal hematocrit and hemoglobin (Hgb) levels. It is interesting to know that sleeve gastrectomy and elevated BMI levels are considered to be the protective factors for developing anemia postoperatively.ConclusionThere was a high prevalence of anemia among bariatric patients postoperatively. Female gender with decreasing hematocrit and hemoglobin levels after the surgery might be more at the receiving end for developing anemia than the other patients. Further longitudinal studies are needed to establish the prevalence and risk factors for developing anemia among bariatric surgery patients.