The information needs of a group of patients taking antihypertensive medication were assessed with special emphasis on the influence of perceived symptoms of high blood pressure and adverse drug effects. All patients of a hypertension clinic currently on antihypertensive medication were included in the study. The response rate to the questionnaire was 85%. Of the 623 patients included, only 31% expressed satisfaction with the amount of information received on adverse effects of their antihypertensive drugs. Patients younger than 50 years explicitly expressed a need for information more often than those older than 64. There were no differences in the expressed information needs between men and women. The reported experience of symptoms related to high blood pressure and adverse drug effects was more common among younger patients than among the elderly. Of those who experienced both adverse drug effects and symptoms, 57% expressed a need for more information, whereas only 30% of those who had no such experiences expressed a need for more information on adverse drug effects. It was concluded that there is a substantial need for more information on adverse drug effects, especially among those who have experienced adverse drug effects or some symptoms of hypertension.