The placenta is a very common, but often underappreciated, surgical pathology specimen. Gross examination of the placenta should be organized and routine, in order to efficiently identify abnormalities; only a proper gross examination will allow appropriate diagnosis. Gross findings and lesions discussed here include those of the umbilical cord (length, knots, coiling, insertion), membranes (discoloration, plaques, insertion), and disc (size, infarcts, abnormal shapes). The histologic findings are also discussed by site: cord (inflammation, thrombosis, remnants), membranes (pigment, lesions, chorionicity of twins, maternal arteriopathy), and disc (villous maturity, infarcts, hydropic change, villitis, specific infections). Finally, there is a discussion of the unifying diagnoses: maternal vascular malperfusion, fetal vascular malperfusion, and the amniotic fluid infection sequence.