The purpose of this study was to examine whether cognitive dysfunction was associated with poor participation in an outpatient treatment program for patients with chronic heart failure and if it was related to specific patient characteristics. Cognitive function was measured with the Mini Mental State Examination (MMSE). Twenty-three of 78 (29%) patients randomized to structured care did not participate in this program and nonparticipation during 6-month follow-up was associated with an MMSE score below the median and a low calculated creatinine clearance (CrCl) (R2= 0.15,p= 0.0025) at entry. In the entire group long duration of heart failure and low blood hemoglobin concentration were independently associated with an MMSE score below the median at entry (R2= 0.14,p< 0.0001). Among elderly patients hospitalized with moderate-severe chronic heart failure, judged to be eligible for a nurse-directed outpatient program after discharge, a low MMSE score predicted nonparticipation in such a program. Cognitive dysfunction, which was related to the duration of heart failure, should be evaluated in the treatment of patients with chronic heart failure.