Digitoxin is frequently used in Norway in the treatment of cardiac failure. Digitalis glycosides may give rise to a number of side effects difficult to separate from disease in the elderly. Six patients aged 77-93 years, treated with digitoxin 0.05 mg/day, were hospitalized due to digitalis intoxication. Mean digitoxin half-life was 25.2 days. This is significantly more than reported in other studies on younger patients. The symptoms of digitoxin intoxication disappeared on discontinuation of medication. The slow elimination of digitoxin may be related to reduced serum albumin concentration. When digitoxin is used in the treatment of heart failure in the very elderly patients, one should be aware of the possibility of digitoxin intoxication, even at a low dose.