This work explores beliefs about malaria, which affected attitudes toward and behavior on the use of insecticide-treated and non-insecticide-treated mosquito nets of Karen communities in Tambon Sam Muen, Mae Ramat District, Tak Province. It was found that the attitudes and behavior depended on social, demographic, geographical and ecological factors and their traditional beliefs and norms. Moreover, they were related to social institutes in their communities. These communities were located in dense jungles with humid weather and natural water sources suitable for being breeding grounds for mosquitoes. Additionally, conventional social contexts and culture had been maintained. Disease prevention was conducted according to their traditional beliefs. Nevertheless, when they had more contact with the outside world, modern medical practices and different disease prevention methods were applied. Malaria was prevalent in their communities. When malaria symptoms were detected, chemical spray, blood tests, and treatments were applied by public health personnel. A local public health center provided medical services and local residents were able to use services from nearby community clinics (pp. 105-107).