One way or another, all species possess the ability to regenerate damaged tissues. The degree of regeneration, however, varies considerably among tissues within a body and among species, with urodeles being the most spectacular. Such differences in regenerative capacity are indicative of specific mechanisms that control the different types of regeneration. In this review the different types of regeneration in vertebrates and their basic characteristics are presented. The major cellular events, such as dedifferentiation and transdifferentiation, which allow complex organ and body part regeneration, are discussed and common molecular mechanisms are pinpointed.