Respiratory infections are widely occurring in livestock worldwide. This work was done to investigate the role of Bovine adenovirus type 3 (BAV-3) in respiratory infection in cattle in Gezira State. A total of 100 cattle lung tissue specimens showing pneumonic lesions were collected from slaughter houses (Medani and Barakat slaughter houses). Specimens were tested for BAV-3 antigen using direct immunoflourescent antibodies test (FAT) and sandwich ELISA. The overall detected prevalence by both tests was 19 percent. A comparison between the two tests was applied on 40 samples. Trials for virus isolation in Vero cells were applied. One sample was isolated in Vero cells and identified using FAT and PCR.