Abstract: Coliform mastitis is widely incriminated as an environmental disease in modern dairy herds. J5 vaccine, Rc mutant with exposed common core antigen, was introduced to control the coliform mastitis. Experimental infection and field trial studies indicated the failure of the vaccine in preventing the infection. Nevertheless, it had significantly reduced the incidents of infection and/or the severity of the disease. In contrast, in Saudi Arabian dairy herds, J5 vaccine failed to accomplish, what was reported elsewhere. Further studies are advised to scrutinize the feasibility of the vaccine in control of the disease in Saudi Arabian dairy herds.