Left ventricular (LV) geometry predicts cardiovascular events. Although obesity is a risk factor for cardiovascular diseases, studies have noted a paradox regarding obesity and prognosis. To our knowledge no studies have determined the impact of obesity on LV geometry as well as mortality in patients with preserved ejection fraction. We evaluated 30,920 patients with preserved ejection fraction, including 11,792 obese patients as well as 19,128 nonobese patients to determine the impact of 4 LV geometric patterns, including normal structure, concentric remodeling (CR), as well as eccentric or concentric hypertrophy and obesity on mortality during an average follow-up of 3.2 +/- 1.4 years. Abnormal LV geometry occurred more commonly in obese than nonobese patients (49% vs 44%, p <0.0001 for the difference in the 4 patterns). In obese patients, CR was the most prevalent abnormal pattern (34%), with eccentric and concentric LV hypertrophy occurring in 7% and 8%, respectively, compared with nonobese patients (32%, 6%, and 6%, respectively). Overall mortality was considerably lower in obese than nonobese (3.9% vs 6.5%, p <0.0001). In both groups, progressive increases in mortality compared with normal structure occurred with CR, eccentric and concentric LV hypertrophy (obese patients 2.8%, 4.8%, 5.3%, and 6.9%, respectively; and nonobese patients 4.3%, 8.4%, 9.6%, and 11.8%, respectively). In conclusion, although an obesity paradox exists, in that obesity is associated with higher prevalence of structural abnormalities but lower mortality than in nonobese patients, our data demonstrate that LV geometric abnormalities are prevalent in both obese and nonobese patients with normal ejection fraction and are associated with progressive increases in mortality.