Marek's disease (MD) is one of the most known clinical neoplastic conditions of chicken The disease was first recognized as clinical entity by Marek in 1907. In Egypt, the disease was first recorded by Shebl et al. (1975) and it has been incriminated for heavy losses due to lymphatic tumors it induces among layer and breeder flocks. The advantage of MDV vaccines and its world wide use was reported in disease decline substantially. The increasing number of available types and combination of MDV vaccines has created a greater need to conduct critical comparisons of the protective efficacy of MDV vaccines. This was the aim of the present investigations where the protective efficacy of different types and combinations of MDV vaccines in chickens were comparatively evaluated by experimental challenge using local isolate of MD- virus and also by field challenge using MD./virus infected litter.