The aim of this study is to report the prevalence and risk factors of recurrent aphthous ulceration (RAU) in patients attending Piramird dental speciality for seeking dental treatment. Study design: A cross-sectional survey was carried out among patients (n=1100) who were visiting the department of oral medicine at Piramird dental speciality center in Sulaimani from December 2011-February 2012. The age range of the patients were between 10-79 years, with mean age of (34.27±14.14). 446 (44.6%) of participants were males and 554 (55.4%) were females, with male/female ratios of 0.80:1. All individuals had to answer specific questions including personal data (age, sex), level of education, occupation and smoking habit; etc. Additional questions were related to the risk factors that might be related to the condition. Chi Square test was used to analyze the data. Result: The life time prevalence of RAU experience was 28.2% (n=282). It was highly significantly more common among females (31.76%) (p<0.004). The most commonly affected age group was 20-29 years (36.28%). The hig - hest prevalence of RAU experience was seen among mere students (36.8%); Among non smokers there were highly significantly more patients with RAU experience (30%) than in heavy smoker patients (12.22%), (p=0.000). 34.4% of patients had family history of RAU. Lips and buccal mucosae were the commonest sites of ulcerations (73.10%), and the major risk factor was stress (43.3%). Conclusion: This study has provided information about the epidemiologic aspects of recurrent aphthous ulceration, Based on the finding of this study, RAU is a common, recurrent painful oral ulceration. This study point to the importance of a thorough history taking to identify the patient's main risk factors to get preventive measures, there - fore treatment will be tailored for each patient accordingly. And the author concluded that stress was the major risk factor, thus, stress-management interventions suggested to be beneficial in reducing RAU recurrence episodes.