Parainfluenza viruses are major pathogens causing respiratory illness, manifesting from mild upper respiratory tract infection to bronchiolitis and pneumonia. This retrospective study aimed at providing clinical and epidemiologic data addressing the parainfluenza virus infection in Taiwan. A total of 39 patients were enrolled in this study from March 1999 to December 2000. Infants and young children were the major susceptible population, with 87.2% of them younger than 3 years. No seasonal trend was noted for parainfluenza type 1 and type 2 infections. One clustering of parainfluenza virus type 3 infections occurred in late spring of 2000 based on collected results. Parainfluenza type 1 viral isolates accounted for all of the cases of croup. Most isolates of parainfluenza virus type 3 were associated with upper and/or lower respiratory tract infections. A substantial proportion of the patients had skin involvement; the identification of one case of possible parainfluenza virus-related erythema multiforme is particularly interesting, especially because the chances of a causal relation between viral infection and skin symptoms are formerly thought to be slight. The identification of parainfluenza virus in illnesses classically considered to be due to other viruses is intriguing and may have important implications in the management of childhood illness clinically.