Respiratory Syncytial Virus (RSV) is an important viral agent of sheep and goat respiratory tract infections. RSV usually replicates in airway epithelium, inducing proinflammatory cytokines and chemokines. In this study, it was aimed to investigate TNF-α expression in natural RSV-infected sheep and goat lung paraffin blocks by immunohistochemical method. The material of the study consisted of 29 lung paraffin blocks (19 sheep and 10 goats), which were admitted to Etlik Veterinary Control and Research Institute with the suspicion of pneumonia from Ankara and surrounding provinces between 2015 and 2020. Histopathological findings such as degeneration and desquamation in the bronchial and bronchial epithelium, fibromuscular hypertrophy, hyperplasia in the peribronchial lymphoid tissue, cell infiltration in the interalveolar septum were common in sheep and goat lung paraffin block tissues. Immunohistochemically, RSV reaction was not statistically significant in sheep and goats in bronchial and bronchial epithelium and cell debris, bronchial glands, interalveolar septum inflammatory cells and cytoplasm of alveolar macrophages (p> 0.05). A statistically significant increase in TNF-α expression was determined in goat lung paraffin blocks compared to sheep (p<0.05). In conclusion, an increase in TNFα expression was detected in native RSV-infected sheep and goat lung tissue. It is thought that the results of the study will contribute to the treatment of sheep and goat respiratory tract RSV infections.