Access to critical care is rapidly growing in areas of the world where it was previously nonexistent and where infectious diseases often comprise the largest disease burden. Additionally, with crowding, mass migrations, and air travel, infectious diseases previously geographically confined are quickly spread across the planet, often in shorter time frames than disease incubation periods. Hence, critical care practitioners must be familiar with infectious diseases previously confined to the developing world. This article reviews selected tropical diseases that are seen in diverse locales and often require critical care services.