Introduction: Despite the bulk of evidence between obesity and cardiovascular complications, the effect of the duration of obesity (DOO) on cardiac function has so far received limited attention. The aim of the study is to study the relationship between a new, American Heart Association (AHA) and World Health Organization (WHO)-adapted formula for reporting DOO with echocardiographic findings and comorbidities in a large cohort of individuals whose BMI ranged from normal (<25 Kg·m^﹣2) to morbid obesity (>40 Kg·m^﹣2) and had been obese for varying lengths of time. Methods: 198 (M60/F138) asymptomatic patients were recruited. Patients were classified according to their reported DOO. The normal weight group (N = 92 (40/F52) was formed by those patients who did not recall maintaining a BMI > 30 Kg·m^﹣2 from age 18 while those recalling maintenance of a BMI > 30 Kg·m^﹣2 since age 18 and thereafter formed the obese group (N = 106 (M20/F86)). A detailed clinical, echo-cardiographic and analytical study was performed. Results: DOO in our series disclosed a significant correlation with left ventricular architecture and hemodynamics, left ventricular mass, cardiac output as well as the prevalence of diabetes mellitus, hypertension and insulin resistance. Stepwise multiple regression analysis revealed that almost 54% of the interventricular septum thickness’s variance can be independently predicted by a model including DOO, gender, hypertension and logtransformed HOMA. Conclusions: Our formula for estimating the duration of obesity provides a simple, user-friendly tool whose utilization in bariatric preoperative assessments and in advanced nursing practice deserves prospective studies.