To analyse the underlying aetiology, precipitating factors and certain socio-demographic determinants in patients admitted to Kenyatta National Hospital, Nairobi in congestive heart failure. Cross sectional descriptive study. All patients aged thirteen years and above of either sex consecutively admitted with clinical diagnosis of congestive heart failure. Kenyatta National Hospital (KNH), a national referral hospital. PATIENT EVALUATION: Detailed history including socio-demographic characteristics and physical examination was done. Patients underwent haematological and biochemistry tests followed by a chest x-ray, ECG and 2D Echo-doppler examination. Blood culture sensitivity was done when clinically indicated. Ninety one patients were studied, 44 males and 47 females. Almost 32% had rheumatic heart disease, 25.2% had cardiomyopathy, 17.6% hypertensive heart disease, 13.2% had pericardial disease while 2.2% had ischaemic heart disease. Three quarters of patients with hypertensive heart disease were above the age of 50 years, while 79% of patients with rheumatic heart disease were below the age of 30 years. Factors associated with patient deterioration leading to admission with congestive heart failure (CHF) included inadequate therapy (27.4%), arrhythmia (20.9%), respiratory infections (17.6%), anaemia (13.2%) and infective endocardiatis. Sixty two per cent of patients investigated were in New York Heart Association (NYHA) functional classification class IV, 31.9% in class III and 5.5% in class II. Congestive heart failure constitutes 3.3% of all medical admissions at KNH. Rheumatic heart disease is the commonest cause of congestive heart failure in our set-up while inadequate therapy, arrhythmias and respiratory infections are the three major causes of decompensation in our patients with cardiac disease.