Abstract The clinical presentation, investigative findings, classification, and management of 17 acute pseudotumors based on patterns of orbital involvement is presented. Acute pseudotumors developed over days to weeks and were dominated by pain, neuropraxia, and inflammatory clinical features. Five patterns of acute inflammatory pseudotumor were seen. Anterior and diffuse acute pseudotumors were characterized by manifestations of inflammation of the globe and orbit including pain, lid swelling, ptosis, diplopia, uveitis, papillitis, optic neuropathy, and exudative retinal detachment. Anterior or diffuse orbital infiltration was noted on computerized tomography (CT) and ultrasound. Lacrimal involvement was characterized by local pain, tenderness, lid swelling and inflammation, with CT and ultrasound confirming an anterior inflammatory mass. Posterior or apical involvement led to an early optic neuropathy, and myositic lesions were characterized by features of muscle infiltration. Management with steroids was effective and could be followed by serial CT studies.