Objective: It has been reported that caries prevalence in patients with aggressive periodontitis (ie, juvenile periodontitis) might be higher than that in matched controls. However, the available results are inconclusive. The aim of this study was to assess this relationship by comparing caries experience among subjects with generalized aggressive periodontitis (AgP) and those with chronic periodontitis (CP) and to identify reasons for tooth loss in both groups. Method and Materials: A convenient sample of subjects with AgP (210) and CP (332) was evaluated for decayed, missing, and filled teeth (DMFT) by both clinical and radiographic methods. Statistical analysis was performed by t test and ANOVA. Results: The AgP subjects have significantly less caries experience than the CP subjects older than 20 (P .001). Tooth loss was mainly due to periodontal disease in AgP subjects and caries in CP subjects. Conclusion: Subjects with AgP have significantly less caries experience than subjects with CP over 20 years of age (P .001). Keywords: aggressive periodontitis, chronic periodontitis, dental caries