The cases of 29 patients aged 20 years or less with orbital inflammatory pseudotumor were studied retrospectively. There was no sex predilection, although the left orbit was involved twice as often as the right. Patients typically had abrupt onset of periocular pain, early-morning swelling, chemosis, conjunctival and extraocular muscle injection, proptosis, a palpable mass, and extraocular motility disturbances. Visual acuity was usually only mildly affected at onset. Forty-five percent of patients had or subsequently developed bilateral orbital involvement in the absence of notable systemic diseases. Papilledema and iritis were seen in 35% of patients, respectively, particularly in bilateral cases. All cases responded to steroids, but bilateral disease was the most apt to become steroid dependent. Permanent functional impairments were seen most commonly in patients who had alternating recurrent bilateral disease or who underwent surgical exploration.