The knowledge of potential complications after surgical removal of third molars and adequate risk assessment is indispensable in oral surgery. The present retrospective study analyzed the influence of different parameters, such as the patients age and gender, retention type, and radiological projection (using orthopantomography) of wisdom teeth on the mandibular canal on postoperative complications after the removal of 1,199 wisdom teeth. Overall, 101 (8.4%) complications occurred: 50 cases of alveolar osteitis (4.2%), 12 temporary (1%) and 6 persistent (0.5%) sensation disorders, 15 abscesses (1.25%), 7 dehiscences (0.6%), 5 cases of post-operative bleeding (0.4%), 4 sequestra (0.32%), 1 fistula (0.08%) and 1 hematoma (0.08%). The risk for developing alveolar osteitis was 6% for patients who suffered from a previous pericoronal infection and was higher for female than male patients. Smoking showed no influence on alveolar osteitis. A significant correlation (p<0.0001) could be shown between the radiological projection of wisdom teeth on the mandibular canal and post-operative sensation disorders. The experience of the surgeon and pre-operative 3-dimensional imaging (cone- beam computed tomography, computed tomography) did not reduce this risk. No correlation was found for patients age and gender. In conclusion, the surgical decision to remove wisdom teeth must be made with caution in cases of complete radiological projection of the wisdom tooth on the mandibular canal.