The objective of this study was to determine the periapical status and the quality of root canal fillings and to estimate the endodontic treatment needs in a German population. Clinical and radiographic data and the operative procedures performed were evaluated on 323 patients coming to a dental surgery in Stuttgart, Germany, in 1993. In 182 individuals at least one tooth exhibited a root canal filling, a necrotic pulp or an irreversible pulpitis. Out of the 7897 teeth examined, 215 (2.7%) had a root canal treatment (category A), 122 being nonendodontically treated (1.5%) did not respond to the sensitivity test (category B) and 53 (0.7%) were diagnosed as having irreversible inflamed pulp tissue (category C). The prevalence of teeth associated with radiographic signs of periapical pathosis was 61 % in the group of root canal filled teeth and 88% in the group of pulpless and non‐endodontically treated teeth. Using the level and the density of the root canal filling as criteria for evaluating the technical standard, only 14% of the endodontic treatments of non‐apicectomized teeth were qualified as adequate. The minimal endodontic treatment need is 2.3% related to all examined teeth when the root canal filled teeth with clinical symptoms of periapical periodontitis (category A) and those of categories B and C are included. The real endodontic treatment need is suggested to be larger when considering that the technical quality of the obturation is poor in most symptomless endodontically treated teeth associated with a periapical lesion. In the case of retreatment of these teeth, the endodontic treatment need would then be calculated at 3.7%.