High-risk pregnancies require specialized obstetric and anesthetic care. A basic understanding of how specific pathophysiology and pharmacologic therapy interact with anesthetic care is essential for both obstetrician and anesthesiologist. This paper selectively focuses on preeclampsia/eclampsia, diabetes mellitus, prematurity, multiple gestations, infectious disease, preexisting neurologic disease, and preexisting cardiac disease, reviewing anesthesia for labor and vaginal and cesarean delivery for each high-risk problem, as practiced at a Level III perinatal unit. Emphasis will be placed, when appropriate, on recent experience with monitoring and aggressive pharmacologic therapy of the critically ill parturient.