Objective: This study aimed to investigate the prevalence of oral mucosal lesions (OMLs) in adult patients who did and did not use tobacco, their habits, and the relative risk of developing oral lesions associated with these habits.

Methods: The present study was a case-control, descriptive, and clinical-pathological investigation, which included 136 subjects, who visited a private dental university in Riyadh. The subjects were divided equally into two groups; the case group and the control group. The type, frequency, duration, and time of tobacco use were recorded. The participants’ oral mucosa was systematically examined, and any alterations or abnormalities were analysed.

Results: In the case group, the correlation between tobacco use and the presence of lesions was positively significant (p = 0.0001). The frequency and duration of tobacco exposure since the commencement of the habit and the age of the individual were not associated with the presence of OMLs (p > 0.05).

Conclusion: This study was conducted to investigate the prevalence of OMLs in adult patient’s users and non-users of tobacco. Tobacco users had a significantly higher risk of developing OMLs as compared to non- tobacco users. The type and location of OMLS varied based on the type and duration of tobacco use.

Keywords: Oral mucosal lesions, tobacco, Smoking, Precancerous lesions, Saudi Arabia