This chapter discusses the passive and active tumor targeting of different polysaccharides as nanocarriers for cancer therapy. There are so many methods of drug targeting like passive drug targeting, "physical" targeting, magnetic targeting, targeting using specific "vector" molecules and active targeting. In passive targeting, macromolecules including nanoparticles accumulate preferentially in the neoplastic tissues as a result of the enhanced permeability and retention (EPR) phenomenon, first described by H. Maeda and Y. Matsumura. The principal schemes of drug targeting include the direct application of a drug into the affected zone, passive drug targeting which is an approach of spontaneous drug accumulation in the areas with leaky vasculature, or EPR effect. The most important challenge in active targeting is defining the most suitable targeting agent or agents to selectively and successfully transport nanoparticle systems to cancerous tissue thus avoiding any kind of toxicity in the process.