The dermatoses of pregnancy can be classified into the following 3 groups: physiologic skin changes in pregnancy, dermatoses and cutaneous tumors affected by pregnancy, and specific dermatoses of pregnancy. Correct diagnosis and classification are essential for the treatment of these disorders, when necessary. Laboratory investigations are required when the diagnosis remains in question despite a careful history and thorough physical examination. A discussion with the pregnant woman about the nature of her skin condition, and the possible fetal risks associated with it, is imperative. (J Am Acad Dermatol 2001;45:1-19.) Learning objective: At the conclusion of this learning activity, participants should be familiar with the dermatoses of pregnancy and the proposed classification of them into 3 main categories. Participants should also have a better understanding of the current knowledge of these conditions to aid in evaluating the patient with a pregnancy dermatosis.