The ability of a molecule to crystallize in different crystalline forms is known as polymorphism. Polymorphism in organic solids is of fundamental importance because of its ability to alter physical and chemical properties in different crystal structures, such as melting point, density, compressibility, solubility, hardness, dipole moment and bioavailability. Understanding the origin of polymorphism and controlling the outcome of crystallization process to avoid undesired forms is a current goal in crystal engineering. Getting the right polymorph is not only important for drugs and pharmaceuticals but also for chemicals like explosives, dyes, pigments, flavors and confectionery products. This approach enables emerging strategies to speed-up pharmaceutical development and capture solid form diversity of pharmaceutical substances.