We investigated 568 consecutive patients undergoing dobutamine stress echocardiography to elucidate the mechanism of left ventricular (LV) obliteration. Baseline clinical and echocardiographic variables were related to dobutamine-induced LV cavity obliteration defined as approximation of LV endocardium associated with an intracavitary flow acceleration of at least 2 m/s in the absence of a distal residual cavity. The LV cavity obliteration was observed in 89 (16%) of the 568 patients and was more frequent in women and those with smaller LV dimensions, increased LV wall thickness, and higher resting ejection fractions. Despite similar peak stress levels, the cavity obliterators were less likely to have chest pain and detectable stress-induced wall motion abnormalities. We conclude that LV cavity obliteration during dobutamine stress is common and is associated with female sex, smaller LV size, presence of LV hypertrophy, and higher LV ejection fraction. Despite similar stress levels, chest pain and reversible wall motion abnormalities are observed less frequently in patients with cavity obliteration, raising the possibility of lower prevalence of coronary artery disease or masking of ischemia in this patient population.