Ulcerative colitis belongs to a group of diseases called inflammatory bowel disease. Although it primarily affects the colon, extraintestinal manifestations of the disease are often apparent, such as lesions in the oral cavity. These lesions may also be the result of medications that are used in the therapy or malnutrition, which is very common among the patients suffering from this disease. Widely varying prevalence rates have been reported ranging from 2 to 34%. The most common lesions include aphtous ulcerations, angular cheilitis, hemorrhagic ulcers and pyostomatits vegetans, which represents a specific marker of active ulcerative colitis,although the nature of this association is not clear. Higher prevalence of certain oral symptoms such as halitosis, xerostomia, tongue coating and taste change has also been reported among the patients with ulcerative colitis. Ulcerative colitis in a certain way affects oral health. Patients with this disease have higher prevalence of caries, periodontitis and bone loss. All these problems imply the need for frequent dental check-ups and informing the patients about the importance of oral hygiene.Oral manifestations can precede the onset of intestinal symptoms and for this reason it is important for the doctor of dental medicine to recognize these manifestations and to promptly forward the patient to a gastroenterologist.