Rhinoviruses are important upper respiratory pathogens that are strongly associated with asthma exacerbations. However, the inflammatory response to rhinovirus infection is poorly understood. Interleukin (IL)-8 has been implicated in the pathogenesis of respiratory viral infections and asthma. Rhinovirus-induced IL-8 release and mRNA induction were examined in peripheral blood mononuclear cells (PBMC), Rhinoviruses induced IL-8 release for up to 7 days after inoculation onto PBMC, This was associated with an increase in IL-8 mRNA expression that peaked 48 h after exposure to the virus. IL-8 protein production was reduced by UV inactivation of the virus and abolished by preventing virus-receptor binding, Although rhinovirus replication was not demonstrated in PBMC, low-grade productive infection was shown in the human monocyte cell line THP-1, Rhinovirus induction of IL-8 in monocytes or airway macrophages may be important in the pathogenesis of rhinovirus-induced asthma exacerbation.