This chapter basically talks about the pathology of placenta. Placenta is the important organ that separates the fetus from the endometrium of the uterus. It is also the main connecting link between the fetus and mother. The placenta consists of multiple villi. The villi are lined by the cytotrophoblast and syncytiotrophoblast and the central core of the villi consists of blood capillaries containing blood. Placenta is a discoid-shaped structure with 3 cm thickness and average diameter 15 to 25 cm. Indications of placental examination include maternal, fetal and placental causes. Normally, the placenta is a single disk-shaped structure. Succenturiate lobe, bilobed, multilobulated placentas, placenta membranacea, fenestrate placenta, extrachorial placenta, circumvallate and circumvaginate are the different abnormalities of the shape of placenta. This chapter also discusses the normal development, abnormal adherence of placenta and multiple gestations. This chapter also provides appropriate detail about the placental inflammation and intrauterine infections, circulatory disorders of placenta: maternal circulatory disorder, and placenta in maternal and fetal disorders. Chorangiosis, pathology of membranes and nontrophoblastic tumors are also discussed in this chapter.