Of 6,148 original cohort and offspring subjects of the Framingham Heart Study who underwent routine evaluation, a healthy group of 347 men (aged 42 +/- 12 years) and 517 women (aged 43 +/- 12 years) was identified to develop echocardiographic criteria for left ventricular (LV) hypertrophy. Healthy subjects were defined as normotensive, receiving no cardiac or antihypertensive medications, nonobese and free of cardiopulmonary disease. Echocardiographic criteria (in accordance with the American Society of Echocardiography convention) for LV hypertrophy, based on mean plus 2 standard deviations for LV mass, LV mass corrected for body surface area and LV mass corrected for height in this healthy sample are, respectively: 294 g, 150 g/m2 and 163 g/m in men and 198 g, 120 g/m2 and 121 g/m in women. Criteria based on LV mass/height result in higher prevalence rates of LV hypertrophy than LV mass/body surface area while still correcting for body size. The prevalence of LV hypertrophy in the entire study population (using LV mass/height criteria) is 16% in men and 19% in women. Until outcome guided criteria for LV hypertrophy are developed, application of sex-specific criteria based on a healthy population distribution of LV mass offer the best approach to echocardiographic diagnosis of LV hypertrophy.