Melanocytes are pigment-producing cells derived from neural crest cells and are responsible for the color of skin. They also have an important role in protection from UV rays. There are multiple steps involved in the synthesis of melanin pigment. Any congenital or acquired defects in the pathway and enzymes involved in the pathway cause pigmentary disorders. The rate of synthesis of melanin, size, and distribution of melanosomes are all involved in the pathogenesis of pigmentary disorders. This chapter explores the development, function, and regulatory mechanisms of melanocytes, as well as the pathogenesis of melanocyte-related disorders.