Left ventricular hypertrophy is associated with an increased risk of coronary heart disease and all-cause mortality. Electrocardiographic criteria for left ventricular hypertrophy have high specificity but low sensitivity. Recent advances in methodology have improved the sensitivity of the electrocardiogram for detecting left ventricular hypertrophy. Criteria for left ventricular hypertrophy have been developed from epidemiologic studies using M-mode echocardiography. The prevalence of left ventricular hypertrophy is influenced by blood pressure, age, sex, and obesity. Recent studies have shown that waist-to-hip ratio, hyperinsulinemia, a dominant late systolic peak in the arterial pressure waveform, and a decrease in nocturnal blood pressure decline are also determinants of left ventricular mass. Left ventricular hypertrophy is associated with an increased incidence of ventricular arrhythmias and with an impairment in coronary flow reserve. Newer imaging techniques, such as two- and three-dimensional echocardiography, magnetic resonance imaging, and ultra-fast computed tomography are more accurate and reproducible than M-mode echocardiography, but these methodologies are expensive and not readily available for assessment of left ventricular mass.