Sleep-disordered breathing (SDB) is common in patients with reduced ejection fraction (EF). However, little is known about the prevalence of SDB in a general heart failure population including patients with preserved EF (HFPEF).We prospectively enrolled stable heart failure outpatients from our heart failure clinic to assess the prevalence of SDB independent of systolic left ventricular function.Among 115 patients (62% with reduced EF, 38% with preserved EF, New York Heart Association Class II-IV) SDB was present in 81% (27% central sleep apnea, 54% obstructive sleep apnea [OSA]). HFPEF patients had SDB in 80% of the cases, 62% had OSA. This group had significantly more hypertension.This study shows a high prevalence of SDB in a general heart failure population, also in patients with HFPEF. These patients have predominantly OSA. Especially in patients with HFPEF SDB should be kept in mind and referral to a sleep specialist should be considered.