Rimantadine was compared with acetaminophen in a double-blind randomly assigned therapeutic trial in 63 children presenting with influenzal symptoms. Fortynine of the children were proven to have influenza A by culture on presentation. Forty-three of the cultures, 88%, were influenza A/H1N1 strains. Both drugs were well tolerated. Rimantadine lowered the amount of virus shed in the first 2 days after initiation of therapy. Clinical resolution of illness was not different between the two therapeutic modalities. In individuals who shed virus for 4 days, strains recovered on the last day were relatively resistant to rimantadine.