The present study determines the cytokine gene expression in chickens following RSV-A infection, using RT-qPCR. In susceptible chickens tumors progressed to fulminating metastatic tumors while it regressed in regressors chickens and some resistant non-responder chickens did not respond to RSV-A infection and thus did not develop tumors at all. The in vivo expression of pro-inflammatory cytokines, Th1 cytokines and Th2 cytokines was determined at the primary site of infection, as well as in different organs of progressor, regressor and non-responder chicks at different time intervals. Our results indicated a significant upregulation of the pro-inflammatory cytokines, IL-6 and IL-8, in all the organs of progressor chicks, while they were significantly lower in regressor and non-responder chicks. The expression of the Th1 cytokines IFN-γ and TNF-α was low in all of the organs of the progressor group, except that in spleen. In contrast, regressor and non-responder groups showed high expression of IFN-γ and TNF-α. Further, there was an early upregulation of the expression of the Th2 cytokine, IL-10, TGF-β and GM-CSF, in all of the organs of progressors as compared to uninfected control.