People with skin of color constitute a wide range of racial and ethnic groups—including Africans, African Americans, African Caribbeans, Chinese and Japanese, Native American Navajo Indians, and certain groups of fair-skinned persons (eg, Indians, Pakistanis, Arabs), and Hispanics. It has been predicted that people with skin of color will constitute a majority of the United States and international populations in the 21st century. There is not a wealth of data on racial and ethnic differences in skin and hair structure, physiology, and function. What studies do exist involve small patient populations and often have methodologic flaws. Consequently, few definitive conclusions can be made. The literature does support a racial differential in epidermal melanin content and melanosome dispersion in people of color compared with fair-skinned persons. Other studies have demonstrated differences in hair structure and fibroblast size and structure between black and fair-skinned persons. These differences could at least in part account for the lower incidence of skin cancer in certain people of color compared with fair-skinned persons; a lower incidence and different presentation of photo aging; pigmentation disorders in people with skin of color; and a higher incidence of certain types of alopecia in Africans and African Americans compared with those of other ancestry. However, biologic or genetic factors are not the only ones impacting on these differences in dermatologic disorders. Cultural practices also can have a significant impact. Further studies are needed to help dermatologists optimally treat people with skin of color. (J Am Acad Dermatol 2002;46:S41-62.)