An enzyme-linked immunosorbent assay (ELISA) was developed for diagnosing human coronavirus (HCV) infections in children. One hundred and seventy seven nose swabs, throat swabs, and nasopharyngeal aspirates were collected from 30 children suffering from acute respiratory infections. These samples were tested for HCV antigens by ELISA and 28.2% of the samples were shown to be HCV positive. These results indicate that our ELISA should prove useful in the diagnosis of HCV infections in children. Further studies are in progress to extend the ELISA to detect HCVs in experimentally and naturally acquired infections in adults.