The impact of the growing obesity epidemic on the outpatient echocardiography laboratory and the characteristics of these patients were retrospectively investigated. Over a 6-month period, 916 patients were referred for study, 49.7% of whom were obese (body mass index >29.9 kg/m(2)), whereas only 22.3% were normal weight (body mass index 18.5 to 25 kg/m(2)). The obese patients were more likely to be female, black, older, and referred because of dyspnea or suspected heart failure (58.1% vs 36.8%, p <0.001). Despite a poorer quality of echocardiographic studies requiring more use of intravenous left heart contrast, the left ventricular ejection fraction was estimated in a similar proportion of these patients (93.9% vs 96.6%, p = 0.016). However, pulmonary artery systolic pressure measurement was less successfully obtained (66.6% vs 80.6%, p = 0.002). Thus, the demographics and referral diagnoses of obese patients differ significantly from normal weight patients, and body habitus presents unique imaging challenges that were only partially met while consuming greater resources.