Obesity rates have been increasing for all population groups worldwide, leading to the increased development of various diseases. This study was designed is to identify the relationships between obesity and several important otorhinolaryngologic diseases, including chronic otitis media (COM), chronic rhinosinusitis, and chronic tonsillitis.Mean body mass index (BMI) was compared in patients with COM, rhinosinusitis, and tonsillitis and in a control group. The relationships among the prevalence rates of overweight and obesity, morbidity period, and BMI were assessed in each group.Mean BMIs in the COM, rhinosinusitis, and tonsillitis groups were 24.45±2.72 kg/m(2), 24.68±3.25 kg/m(2), and 24.67±3.82 kg/m(2), respectively, with each significantly higher than in the control group (23.22±3.01 kg/m(2), P0.05 each).Mean BMI and the prevalence of obesity were elevated in the three groups of patients with representative otorhinolaryngologic inflammatory diseases, including COM, chronic rhinosinusitis, and chronic tonsillitis.