Recurrent aphthous stomatitis (RAS) is one of the most common causes of mouth sores in children so the management of this condition is a matter of great importance. YouTube is increasingly being used by patients to obtain health-related information. The aim of this work is to examine the quality of information offered by YouTube about mouth sores in children (MSC). Searching the term mouth sores in children, (MSC) displayed 12.300 results. Of the top 60 videos analyzed, 31 were excluded following exclusion criteria. The major source of upload was from healthcare information channels (HC-41,38%), followed by individual users (HP-25.59%), healthcare professionals (IU-17.24%) and generalist information channels (HC-13.78%); 20.69% of them deal with predisposing factors, and related pathologies, the majority of these propose home remedies (60.72%) rather than topical analgesic drugs (21.43%), antimicrobials (7.14%) and topical steroids (3.57). Most of the videos analyzed were slightly useful (68.97%). Information about mouth sores in children on YouTube was poor regardless of the upload source. Analyzing health content on social platforms is a starting point for providing greater quality of health-related information.