Genetic information is beginning to have a direct impact on patient care and it is important that cardiologists appreciate the value and approaches to associating genetic variation and health outcomes. Genetic associations should be based on compelling genetic and biological hypotheses and should be statistically sound so as to reduce the possibility of "false discovery" in the setting of testing multiple hypotheses. Study designs should clearly define cases and controls and measurement of phenotypes. Finally, findings should be replicated in at least 1 independent cohort. Consideration of these principles should provide insight into disease biology based on genetic findings and encourage their meaningful adoption into clinical practice.