Aim. To define the prognostic value of arterial hypotension (AH) episodes in patients with chronic heart failure (CHF). Subjects and methods. One hundred and ninety-nine patients (mean age 57.2±10.5 years) were examined. Functional Class I, II, III, and IV CHF was diagnosed in 24, 92, 82, and 1 patients, respectively. The cause of CHF was coronary heart disease concurrent with hypertensive disease in 160 patients. AH was diagnosed when their blood pressure (BP) was 100/60 mm Hg during medical visits and daytime BP 100/60 mm Hg and nocturnal BP 85/47 mm Hg were measured during 24-hour BP monitoring (BPM). The follow-up lasted 24 months. The major end-point was a combined measure of death rates from any cause, incidence rates of myocardial infarction (MI) or stroke. Results. AH was identified in 6.5% of the patients with CHF when BP was measured during their medical visit; 24-hour BPM revealed hypotensive episodes in 65.8%. There were no differences in the major endpoint in relation to the presence of AH episodes. MI developed only in patients with systolic AH episodes (5 versus 0 patients; ξ2=5.55; р=0.02) and the risk of MI was associated with the greater magnitude of diastolic AH. Conclusion. 24-hour BPM can substantially increase the detection rate of potentially dangerous BP changes. Almost three fourths of patients with CHF were observed to have AH episodes during a day. The use of angiotensin-converting enzyme (ACE) inhibitor/diuretic, ACE inhibitor/mineralcorticoid receptor antagonist, ACE inhibitor/nitrate combinations in the treatment of patients with CHF increase the risk of transient AH. In patients with CHF, the risk of MI is associated with the detection of systolic AH episodes and the magnitude of diastolic AH.