We studied the effectiveness of nasal decongestant-antihistamine in treating acute sinusitis in children. All subjects received oral amoxicillin for 14 days. Subjects randomized to the decongestant-antihistamine group received nasal oxymetazolone and oral syrup containing brompheniramine and phenylpropanolamine. Controls received placebo nasal saline and oral syrup. In both groups symptoms resolved quickly, and radiographs improved significantly. Responses to treatment were similar between the two groups. Water's radiographs of the maxillary sinuses proved reliable in the assessment of the degree of sinus involvement. We conclude that decongestant-antihistamine need not be given to the child with acute maxillary sinusitis.