Acute bacterial sinusitis is usually a clinical diagnosis. Orbital complications require emergent evaluation with computed tomography. Using the orbital septum as an anatomic landmark, such infections can be classified as pre- or postseptal and treated with the most adequate therapy, ie, oral or intravenous antibiotics or surgical endonasal drainage. Intracranial complications can be seen in 3.7% to 11% of these patients, often with subtle clinical symptoms and signs. Radiologists play a decisive role in the final management of these patients and should be familiar with the most relevant complications. In this article, we present a retrospective review of all pediatric patients referred to our department for paranasal sinuses and orbital computed tomography because of acute complicated bacterial sinusitis. They were studied with an emergent enhanced facial and cranial computed tomography within 24 hours of admission, followed by magnetic resonance imaging when intracranial complications were suspected. Particular emphasis is placed on the imaging algorithm and the most relevant complications; we correlate imaging findings with clinical and bacteriological data.