A one-step diagnostic test based on an immunochromatographic (IC) assay for adenovirus was evaluated with purified adenovirus and clinical specimens. According to five clinically common serotypes of purified adenovirus tested, the IC test was more sensitive than two commercially available enzyme immunoassay (EIA) test kits. For tonsilopharyngeal specimens from 63 febrile pediatric patients with suspected adenoviral upper respiratory tract infection, the sensitivity and specificity of the IC test against viral isolation by cell culture was 88.5% (23/26) and 100% (37/37), respectively. The IC test, which is quicker and easier to perform than EIA test kits, is very useful in the rapid diagnosis of adenoviral upper respiratory tract infection of pediatric patients.