Carbohydrate antigens are the most abundant antigens expressed at the cancer cell surface and have been shown to be uniquely effective targets for immune recognition and attack. The basis for cancer vaccines that primarily induce an antibody response, such as vaccines against these carbohydrate antigens, is now well established in both experimental models and the clinical setting. In both cases, antibody administration or induction has been especially effective in the adjuvant setting when the targets are circulating tumor cells and micrometastases. The patterns of carbohydrate antigens expressed by different tumor types has been established, paving the way for polyvalent-antibody-inducing vaccines. This then forms the rationale for the construction and testing of carbohydrate vaccines against cancer, the focus of the second part of this review.