This study investigated how support from other organisations compliments or reinforces the activities of teachers and parents in order to optimise the development and improvement of students in inclusive classrooms in Thailand. The objectives of this study include: (1) investigating the changes in teachers and parents who joined a municipal Human Resource Development (HRD) program in Khon Kaen Municipality; (2) evaluating the success of the program against its expected results; and (3) analysing the results and proposing improvements to the program to benefit students with disabilities. In order to examine the overall outcomes of the program for the concerned parties, qualitative survey-based research involving questionnaires, interviews and focus group discussions, employed with school administrators, teachers and parents, was used. The major findings are that school administrators and teachers paid more attention to students with a diversity of needs after joining the program, although participating parents' acceptance of students with disabilities was low. The program evaluation revealed that participating teachers managed their classrooms better. Lastly, in order to improve the program in the Thai context, more acceptance and awareness must be created among both teachers and parents.