Background The purpose of this study was to assess the association between chronic kidney diseases (CKD) and dental caries. Material and Methods 107 patients with CKD and 107 with no systemic alteration were randomly included. DMFT (decayed, missing, and filled teeth), plaque index, colony-forming units (CFU) of Streptococcus mutans and salivary composition (IgA total, IgA anti- Streptococcus mutans, calcium and urea) were evaluated. McNemar and Wilcoxon tests were used to compare test and control groups. Spearman test was used to correlate time of hemodialysis and variables studied. Associations between variables were evaluated by logistic regression analysis. Results The number of filled teeth, the amount of IgA anti-Streptococcus mutans, salivary urea, education level, monthly income and the amount of CFU of Streptococcus mutans were statistically different between groups. There was a positive correlation between the duration of hemodialysis (Hd) and the amount of IgA anti-Streptococcus mutans, urea in saliva, and the number of CFU of Streptococcus mutans. In the adjusted model, a higher incidence of CFU mutans streptococci, elevated salivary urea, smaller number of filled teeth, lower DMFT, and less calcium salivary were associated with CKD. Conclusions Programs to prevent and treat oral problems and regular follow-up at the beginning of dialysis are necessary to increase patients’ awareness of their condition. Key words: Renal disease, chronic, dental caries, renal dialysis.