The aim of this thesis was to investigate the relationship between diabetes knowledge, attitudes, self-management, and quality of life (QoL) of people with Type 2 Diabetes Mellitus (T2DM). The main hypothesis was there would be significant relationships between diabetes knowledge, attitudes, self-management, and QoL in the path model. I conducted two studies on two different populations, one in Australia and the other in Malaysia. In addition, these two samples represented different cultures. In research on the Australia-based population, I examined the relationship between diabetes knowledge, attitudes, self-management, and QoL in people with T2DM living in Melbourne, Australia. In research in the Malaysia-based population, I examined the relationship between diabetes knowledge, attitudes, self-management, and QoL in people with T2DM living in Kelantan, Malaysia.