The authors point out the similarity of the clinical picture of insulinoma and panic disorder. Clinical tests and laboratory methods necessary for proper diagnosis are described in the first part of the article. A case-report of a patient who was admitted for symptomatic psychotic syndrome due to insulinoma is the subject of the second part of the article. Panic episodes with subsequent delirium states occurred in this patient at the beginning of the disease. These symptoms, which caused severe hypoglycaemia imitated primary psychiatric disease. Psychopharmacotherapy without glucose supplementation could lead to brain damage and event do the patient’s death. Therefore, early diagnosis and surgical treatment were necessary to save the patient’s life. Moreover, appropriate insulinoma treatment also prevents recurrent hypoglycaemia and subsequent secondary brain damage and improves the quality of life.

        Key words: insulinoma, panic disease, hypoglycaemia, case-report.