Avian necrotic enteritis is a common bacterial disease in poultry caused by Clostridium perfringens. In this study we evaluated whether NetB, a major virulence factor in necrotic enteritis, could be used as a protective antigen as a subunit vaccine or supplemented in either traditional bacterin or toxoid vaccines. Immunisation with bacterin or cell free toxoid supplemented with recombinant NetB significantly protected birds against necrotic enteritis following heavy challenge with homologous and heterologous strains of C. perfringens, while recombinant NetB alone was only protective against a mild challenge. Birds immunised with recombinant NetB alone or supplemented in bacterin and toxoid had significantly higher levels of NetB specific IgY antibodies compared to groups immunised without additional recombinant NetB. Vaccination using toxoided culture supernatant supplemented with recombinant NetB resulted in the highest protection against necrotic enteritis. This is the first study that shows NetB can be used as a vaccine to protect chickens from necrotic enteritis.