ObjectiveTo determine whether the systemic diseases diabetes mellitus (DM) and arterial hypertension (AH), and smoking are associated with apical periodontitis (AP) in a representative rural population.Materials and methods Cross-sectional study using a representative sample of individuals obtained from a population-based epidemiological survey carried out in the rural area of the city of Rosário do Sul, RS, Brazil, from March 2015 to May 2016. Data were collected through structured questionnaires and clinical examination. Binary logistic regression analysis was performed to identify variables independently associated with AP.ResultsOf the 584 individuals included in the study, 353 (60.4%) had AP. The presence of AP was independently associated with age (odds ratio [OR] = 1.018, 95% con dence interval [CI]: 1.001-1.035, p = 0.041), active or former smoker (OR = 2.109, 95% CI: 1.256-3.540, p = 0.005) and DM or prediabetes (OR = 1.696, 95% CI: 1.164-2.471, p = 0.006) ConclusionThe study identi ed signi cant associations between AP and clinical risk factors. However, it is essential to acknowledge the study's limitations and recommend conducting longitudinal studies to con rm these associations and explore other potential variables involved in the development of AP.Clinical Relevance The study emphasized the signi cance of comprehending and managing risk factors in preventing and treating AP.