Background. Delusional parasitosis (DP) is a monosymptomatic hypochondriacal psychosis where the patient has the delusion of being infested with parasites, whereas Morgellons disease (MD) is described when the patient has fixed ideation of fibers or other materials emerging from skin. Both psychological and organic causes can result into the delusion of infestation, and careful examination is required to exclude secondary causes. Oral DP can result in self-inflected mutilations of the oral mucosa. To our knowledge, oral DP is only rarely reported in the literature. Here, we describe and discuss the management of a case of overlap between oral DP and oral MD at the oral medicine (OM) clinic. Case Report. A 50-year-old male presented to the OM clinic with ulcerations of oral and perioral tissues. Patient reported inflicting wounds to himself using a shaving blade to extirpate worms and pieces of glass from underneath his oral and perioral mucosa. Clinical and laboratory investigations ruled out parasitic infestations. Self-inflected ulcers were treated with topical steroids and prophylactic antifungals, and the patient was referred for psychiatric evaluation. A diagnosis of primary DP was reached, and the patient was managed with antipsychotics. Practical Implications. Oral health care providers should be familiar with oral manifestations of psychiatric disorders and should be able to manage such patients in a multidisciplinary team of internist, dermatologist, and psychiatrist.