Crohn’s disease belongs to the group of chronic inflammatory bowel diseases. The aetiology of this condition is multifactorial and so far has remained unclear. Apart from typical abdominal symptoms, some extra-intestinal manifestations, located e.g. in the oral cavity, may occur in the course of the disease. The purpose of the study was to present oral mucosal lesions in two patients with Crohn’s disease. The clinical picture of the oral mucosa, the results of accessory investigations and therapy in two adults with Crohn’s disease are presented here. The described pathological mucosal lesions included ulceration and buccal mucosa cobblestoning. Oral lesions observed in the course of Crohn’s disease may be both symptoms of the disease and a complication of prolonged systemic pharmacological therapy.