Patient information is an integral part of all dental treatment, endodontic treatment is no exception. Many patients, particularly those who have no earlier personal experience of endodontic therapy, may be afraid of pain, although modern endodontic treatment is practically or totally painfree. The treating dentist must always inform the patient of at least the following aspects of the treatment: 1) probability of pain, 2) number of appointments needed and the duration of each appointment, 3) prognosis of the treatment and possibility of complications, 4) other treatment possibilities including no treatment, and 5) cost of the treatment. In addition, etiology ("reason") for the endodontic disease should be told to the patient on a general level.