The misdiagnosis rate of diverticulitis based solely on clinical and laboratory criteria is high and given the potential severity of diverticulitis and its complications, early and routine radiologic evaluation is recommended. Imaging is used to establish the diagnosis and its extent and severity, and to detect the presence of any complications so that management can be directed appropriately. The most widely used examinations for the diagnosis of diverticulitis are ultrasound, barium enema, computed tomography (CT), and recently, magnetic resonance imaging. Over the past decade CT has replaced barium enema mainly because of its ability to identify extracolonic extent of disease. CT scan remains the procedure of choice in the acute, symptomatic stage. Nevertheless, diverticulitis often remains a clinical diagnosis; thus communication between the clinician and the radiologist remains imperative to facilitate effective testing.