High technology advances in polymer science have opened up new opportunities in drug delivery systems. This chapter broadens the existing information in the field of polymeric materials and polymeric carriers for drug delivery applications. Also, further information about polymeric carriers in linear properties, polymeric carriers with spherical features, and polymerization methods are given. The purpose of using polymeric carriers is to provide patients with a better quality of life and to avoid the side effects of traditional methods. Finding new polymeric carriers is of great importance for drug distribution, especially in the medical world, so new approaches need to be found.