Summary. Aim. This review offers a brief summary of three of the more commonly surveyed and reported oral mucosal conditions found in children, and an appraisal of the variation between selected elements of prevalence study methodologies. Design. Searches of electronic databases (i.e. MEDLINE, CINAHL, EMBASE and EBM Reviews) were conducted to find publications related to oral mucosal conditions in children. Studies were included and reviewed if they contained data on the prevalence of any of the following oral mucosal conditions: geographical tongue, oral ulceration and herpes labialis in children or adolescents (up to the age of 19 years). Results. A total of 29 articles out of 333 met the inclusion criteria and were reviewed. Of these 29 reports, 18 considered geographical tongue, 12 herpes labialis and 10 oral ulceration, although a number of the surveys reported on more than one condition. The approaches used in these studies varied on a number of the potentially important areas associated with validity, comparability, and whether or not the findings may be extrapolated beyond the study population, such as the sampling frame, diagnostic criteria, training and calibration, and examination features. Conclusion. Although there were a number of surveys relating to the prevalence of geographical tongue, herpes labialis and oral ulcers in children and adolescents, reported prevalences varied and few studies were directly comparable in terms of the methodology applied. In particular, there was substantial variation between surveys in terms of the diagnostic criteria and method of detection employed although, in many instances, there was inadequate detail to allow full appraisal of the methodology. There is a need for more good-quality epidemiological studies in this area.