This study was undertaken to examine the prevalence and technical quality of root fillings and the periapical status of endodontically treated teeth in a French subpopulation. Full-mouth periapical radiographs were obtained from 208 consecutive adult patients seeking care within the dental service provided by the Hôtel-Dieu in Paris. The occurrence and technical quality of root fillings were assessed for each root according to the position and the density of the obturation. The periapical status was evaluated using the Periapical Index Scoring System. The type of coronal restoration and the presence of posts were also noted. Of the 8743 roots included in the survey, 23% were root-filled. An acceptable standard of treatment was found in 21% of roots with 16% of these cases associated with signs of periapical disease. In roots with unacceptable root-fillings, 27% had periapical pathology. A post was seen in 26% of the root-filled canals, with 29% of these cases associated with periapical pathology. An intracoronal restoration existed in 30% of the filled roots, of which 22% exhibited a periapical lesion. An extra-coronal restoration was present in 60% of the filled roots, of which 24% had radiographic signs of periapical pathology. The remaining 10% of filled roots that had no coronal restoration were associated with periapical pathology in 33% of cases. At least one periapical lesion was seen in 63% of the patients. The results demonstrate a high prevalence of root-filled teeth and poor technical quality of treatment. Roots presenting with acceptable root fillings were associated with a lower prevalence of periapical pathology (P < 0.001). Posts in roots were associated with periapical pathology significantly more than in roots without posts (P < 0.001).