Introduction: Dry socket (DS) is the most common post‑surgical complication following extraction of impacted molar teeth. Various risk factors have been mentioned for this complication including gender, age, amount of trauma during extraction, difficulty of surgery, inappropriate irrigation, infection, smoking, and oral contraceptive use. The aim of the current study was to evaluate the incidence of DS among surgical removal of impacted third mandibular molar in an Iranian Oral and Maxillofacial Clinic and also identifying the background risk factors.Materials and Methods: A total of 189 patients with a total of 256 surgeries entered this study. Surgeries to remove impacted third mandibular molar teeth between April 2009 and August 2010 were included in this study. A questionnaire containing two sections was designed; in the first section demographic data along with smoking status, oral contraceptive use, menstrual cycle phase, systemic disorders, and use of antibiotics prior to surgery collected; in the second section data regarding difficulty of surgery according to radiograph and surgeon perception after surgery, length of surgery, and number of anesthetic carpules along with data regarding cases returning with DS recorded. Data were reported descriptively and analyzed with Fisher’s exact test and Chi‑square with the confidence interval of 95%.Results: The incidence of DS was 19.14%. Age, gender, systemic disorder, and antibiotics use prior to surgery revealed no significant associations with DS (P > 0.05). However, incidence of DS was significantly relevant to smoking, oral contraceptive use, menstruation cycle, difficulty of the surgery according to pre‑surgery radiograph evaluation and perception of surgeon post‑surgery, length of surgery, and number of carpules used to reach anesthesia (P < 0.05).Conclusion: It is recommended to identify high risk groups when performing extraction surgeries to consider measures in order to reduce postoperative complications.Keywords: Alveolar osteitis, dry socket, incidence, impacted third molar, risk factorsNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue