To determine the appropriate early management of orbital cellulitis and the current bacterial etiology and to evaluate the clinical usefulness of orbital computed tomographic imaging for this infection, a prospective study of orbital cellulitis was conducted during a 2-year period, 1999 to 2000, after the introduction of a conservative medical management plan designed by our pediatric infectious diseases, ophthalmology and otolaryngology services. Basically patients did not have surgical intervention unless progressive involvement of the optic nerve occurred after 24 to 36 h of intravenous antimicrobial therapy. Nine patients had orbital cellulitis and subperiosteal abscesses; only one required surgical drainage because of progressive disease, this case being culture-negative. One had a blood culture positive for Streptococcus pneumoniae; conjunctival cultures showed moderate to heavy growth for S. pneumoniae from this and two other patients, but otherwise bacterial etiology could not be defined. Haemophilus influenzae was not recovered from any of their blood or conjunctival cultures. This experience, during the computed tomography scan and Haemophilus vaccine era, supports an initial medical management approach for most patients with subperiosteal or retrobulbar abscesses resulting in orbital cellulitis.