Misconceptions about cancer may increase the level of fear in the general public and render coping more difficult in cancer patients. The aim of this survey was to study the level of knowledge and misconceptions. Materials and Methods: A questionnaire comprising 27 questions related to cancer etiology, treatment, and prognosis was mailed to 100 patients with gynecological cancers and to 120 healthy women. Results: The response rates were 86 and 78%, respectively. The proportion of correct answers was similar in both groups. Everyone considered cancer to be noncontagious. A majority knew that gynecological cancers have a good prognosis if diagnosed in early stages and that morphine is very effective in the treatment of severe cancer pain, but believed that it causes addiction. Questions with a significant proportion of erroneous answers were related to hormones and cancer. Patients were more aware of the risk associated between unopposed estrogen therapy and endometrial carcinoma (P < 0.05). However, the patients incorrectly believed that combined hormonal therapy (estrogen + gestagens) also increased the risk of endometrial and ovarians carcinoma and they did so much more often than the control group (P < 0.05). The general public more often believed that cancer often arises as a consequence of previous physical injury (P < 0.05). Formal education correlated positively with correct responses (P < 0.01). In conclusion, the results emphasize the importance of proper information about cancer and cancer treatment, especially with regard to hormonal treatment and the use of morphine. Individuals with the least formal education constitute an especially important target group for information. (C) 1997 Academic Press.