Background: Complementary and alternative medicine (CAM) may offer benefits as well as risks to people with cardiovascular disease. Understanding the prevalence and the nature of CAM use will encourage beneficial CAM therapies, prevent potential herb-drug interactions and foster communication between patients and physicians. Methods. A systematic search of eight bibliographic databases was conducted for studies that investigated CAM use in patients with cardiovascular diseases. Two independent reviewers selected relevant abstracts and evaluated the quality of included studies. Results: Twenty-seven studies were included. Prevalence of CAM use in cardiac patients ranged from 4% - 61%. Biologically-based therapies usage ranged from 22% to 68%. Herbal medicines were used by between 2% and 46%. A large proportion of patients did not inform medical practitioners about their CAM use and up to 90% of treating physicians did not discuss CAM use with their patients. Conclusions: CAM use in patients with cardiovascular disease appears common. The findings suggest that the effects of CAM on medical management of cardiovascular disease may be overlooked and that patient-physician communication need to be strengthened.