Frailty is a geriatric syndrome of increased vulnerability to stressors that has been implicated as a causative and prognostic factor in patients with cardiovascular disease (CVD). The American Heart Association and the Society of Geriatric Cardiology have called for a better understanding of frailty as it pertains to cardiac care in the elderly. The aim of this study was to systematically review studies of frailty in patients with CVD. A search was conducted of Ovid MEDLINE, EMBASE, the Cochrane Database, and unpublished sources. Inclusion criteria were an assessment of frailty using systematically defined criteria and a study population with prevalent or incident CVD. Nine studies were included, encompassing 54,250 elderly patients with a mean weighted follow-up of 6.2 years. In community-dwelling elders, CVD was associated with an odds ratio (OR) of 2.7 to 4.1 for prevalent frailty and an OR of 1.5 for incident frailty in those who were not frail at baseline. Gait velocity (a measure of frailty) was associated with an OR of 1.6 for incident CVD. In elderly patients with documented severe coronary artery disease or heart failure, the prevalence of frailty was 50% to 54%, and this was associated with an OR of 1.6 to 4.0 for all-cause mortality after adjusting for potential confounders. In conclusion, there exists a relation between frailty and CVD; frailty may lead to CVD, just as CVD may lead to frailty. The presence of frailty confers an incremental increase in mortality. The role of frailty assessment in clinical practice may be to refine estimates of cardiovascular risk, which tend to be less accurate in the heterogenous elderly patient population.