Objectives: To study the severity of symptoms and estimate the prevalence of oral mucosal lesions in a non-referral adult Swedish population, as registered by general dental practitioners. This study also aims to evaluate the possibility of dental practitioners collecting large quantities of reliable and accurate clinical data on oral mucosal lesions. Study Design: Data from 6,448 adult Swedish patients were collected by general dental practitioners using a standardized registration method. A correlation analysis between a group with oral mucosal lesions and a control group, with no oral mucosal lesions, was performed for various parameters such as symptoms from the oral mucosa, systemic diseases, medication, allergy history, tobacco habits and the patient's own assessment of their general health. In addition, clinical photos were taken of all oral mucosal lesions in order to determine the degree of agreement between the diagnoses made by general dental practitioners and those made by oral medicine specialists. Results: A total of 950 patients (14.7%) presented with some type of oral mucosal lesion and of these, 141 patients (14.8%) reported subjective symptoms. On a visual analogue scale, 43 patients (4.5%) scored their symptoms <30, 65 patients (6.8%) scored their symptoms >=30, and 28 patients (2.6%) scored their symptoms >=60. The most debilitating condition was aphthous stomatitis and the most common oral mucosal lesion was snuff dipper's lesion (4.8%), followed by lichenoid lesions (2.4%) and geographic tongue (2.2%). There was agreement between the oral medicine specialists and the general practitioners over the diagnosis of oral mucosal lesions on the basis of a clinical photograph in 85% of the cases (n=803). Conclusions: Nearly 15% of the patients with oral mucosal lesions reported symptoms. General practitioners could contribute significantly to the collection of large quantities of reliable and accurate clinical data, although there is a risk that the prevalence of oral mucosal lesions may be underestimated.