Clinical studies have indicated the existence of an “obesity paradox” in patients with chronic heart failure (HF), that is, reduced mortality in patients who have elevated body mass index (BMI) scores compared with normal-weight reference groups. The aim of this study was to investigate the relation of BMI with all-cause and cardiovascular (CV) mortality and hospitalization in patients with chronic HF though a systematic review and meta-analysis of published research. PubMed, the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central, Scopus, web of science and Embase were searched for studies reporting rates of total mortality, cardiac mortality, and risk for hospitalization in patients with HF in various BMI categories (<20 kg/m2 [low], 20 to 24.9 kg/m2 [normal reference], 25 to 29.9 kg/m2 [overweight], 30 to 34.9 [obese], and ≥35 kg/m2 [severely obese]).