This research is aimed to formulate the effective teacher teamwork program in municipal schools in Thailand. Primary survey on current situation and problem was conducted to develop the plan to suggest potential programs. Samples were randomly selected from municipal schools by using multi-stage sampling method in order to investigate their organization's situation and problem. Program for effective teamwork is an approach to enhance their working condition using collaboration of all teachers. Data analysis was the descriptive data using direct observation and questionnaire as data collection tools. Effectiveness of the program was reported in high satisfaction level due to its various applications for certain context. Collaboration was a key factor to enhance program effectiveness because of core values that participants held to achieve mutual goals. Suggestion in future study related to this research deals with administrators and organization's sponsorship for their teachers' awareness in team building for organizational effectiveness. Moreover, application of this research method on other types of organization may yield different research findings worth for investigation.