Abstract: The present invention provides a lung simulator comprising a substantially-rigid, fluid-tight, translucent housing simulating a human thoracic cavity and at least one flexible air-tight bag simulating a lung having a plurality of simulated lung lobes, and a corresponding plurality of valves, each of the plurality of valves coupled to a one of the plurality of simulated lung lobes and configured to simulate varying degrees of fluid flow resistance. In a preferred embodiment, the substantially-rigid, fluid-tight, transparent housing has isolated simulated left and right thoracic cavities therein and the at least one flexible air-tight bag is located within one of the simulated thoracic cavities. The present invention further provides a method of manufacturing a lung simulator.