The Far Eastern pattern of mortality, first identified in 1980, is characterized by some of the largest sex differentials at adult ages to be found anywhere in the world. These atypically high levels of excess male mortality were present in several Far Eastern populations during the 1960s and 1970s and have progressively disappeared since that time. This study uses cause of death data to determine the diseases responsible for the existence and attenuation of these sex differences in Hong Kong, Singapore and Taiwan. The analysis focuses primarily on two hypotheses – regarding the roles of respiratory tuberculosis and liver diseases associated with hepatitis B infection – which were proposed to explain the Far Eastern pattern but were never tested. The results of our analysis indicate that respiratory tuberculosis is the single most important cause underlying the existence and attenuation of the Far Eastern pattern, that the role of liver diseases is far from clear cut, and that other causes (such as cardiovascular diseases) are important as well. Some of the risk factors which may underlie these exceptional mortality patterns are identified.