The aim of this cross-sectional study was to evaluate the association between periodontitis and different severities of Chronic Kidney Disease(CKD) in pre-dialytic patients.Demographic, socioeconomic and medical data of 139 patients from the nephrology service of one university hospital in Porto Alegre, Brazil were obtained through interview and clinical records. Full-mouth six-sites-per-tooth periodontal examinations were performed. Associations between periodontitis, stages of CKD and estimated glomerular filtration rate(eGFR) were estimated by multivariable models adjusted for sex, smoking, vitamin-D supplementation, physical activity and renal treatment duration. CKD was classified based on eGFR(<60 ml/min/1.73m ) estimated by the Chronic Kidney Disease Epidemiology Collaboration equation.Patients with severe periodontitis, compared to those without severe periodontitis, had 2.8(CI95%1.25-6.62) and 3.4(CI95%1.27-9.09) times higher risk of being in stages 4 and 5 of CKD, respectively. Having ≥ 2 teeth with clinical attachment loss(CAL) ≥6mm increased 3.9 times the risk of being in stage 5 of CKD. Patients with severe periodontitis and ≥ 2 teeth with CAL ≥ 6mm had 4.4ml/min/1.73 and 5.2 ml/min/1.73 lower eGFR(p-values < 0.05), respectively.Severe periodontitis was associated with poor renal conditions in pre-dialytic CKD patients, strengthening the importance of periodontal evaluation in such patient population.