Objectives: In Palestine, there are no data about the prevalence of oral lesions or their associated risk factors. Thus, this study came to assess the prevalence and the risk factors of oral lesions among adult dental patients visiting Al-Quds University (AQU) Dental Clinics. Materials and Methods: Three hundred Twenty patients were diagnosed clinically for the presence of oral lesions at oral medicine clinics at Al-Quds University in the period between 2015 to 2016. Their age ranged from 21 to 60 years old (mean age: 40.2 ± 17.6). Senior students were trained to conduct the oral exam under the direct supervision of Oral Medicine specialist. Trained students also collected data on patients’ demographics, dental history, medical history and other health related habits. Descriptive and bivariate analyses were generated to describe lesions prevalence and associations with other suggested factors. Results: A total of 68 lesions were found in this study (29.4% of study’s sample). Recurrent aphthous ulcer, traumatic ulcer and geographic tongue were the most common oral lesions. Ten oral potentially malignant lesions were diagnosed (8 cases were Leukoplakia, 2 cases were erythroplakia). Non filtered smoking cigarettes were associated with reported lesions. Oral lesions were noticed to increase with age. Oral lesions were more common on the Tongue, labial and buccal mucosain this study. Conclusions: This study revealed high prevalence of apthous and traumatic ulcer while potentially malignant lesions like leucoplakia and erythroplakia were also seen in patients who were smokers. Dentists should have a high level of awareness during oral examination and intervention should be performed to raise awareness among the population about the harmful effects of smoking on oral health.