Lung development requires carefully regulated coordination of anatomic, physiologic, and biochemical processes. The result of these maturational events must be an organ having an adequate surface area, sufficient vascularization, and the metabolic capability to sustain oxygenation and ventilation during the neonatal period. Recent investigative efforts have greatly increased our understanding of fetal lung maturation by defining the composition of lung surfactant, by documenting changes in the concentration of surfactant components throughout gestation, and by identifying the role of potential metabolic regulatory mechanisms governing lung phospholipid synthesis and turnover. Accordingly, this review addresses salient features of lung development in a multidisciplinary fashion with emphasis on recent biochemical observations and their implications.