The purposes were: (1) review relevant literature on program development, its principles and related concepts as a basis for developing a preliminary framework for Thai extension program development, (2) use framework as a tool to compile a questionnaire for identifying perceptions of importance of various phases of the proposed program development framework, (3) determine differences and similarities in perceptions of some selected aspects of program development, and (4) suggest guidelines to assist Thai operating-level extension personnel for program development;Data were collected by means of a questionnaire consisting of two parts: independent variables (years of service, highest education levels, and major areas of study) and perceptions toward seven phases of the proposed framework and three selected aspects of program development (involvement of people, factors influencing decisions about program development, and coordination with agencies). The questionnaire was based on the proposed framework of program development. Data were analyzed from 626 Thai District Agricultural Officers. The statistical procedures employed were: SPSS subprogram ONEWAY, T-Test, and CROSSTABS to assess differences in Thai District Agricultural Officers' perceptions by independent variables; FREQUENCIES to describe variables; FREQUENCIES and CROSSTABS to assess perceptions of the proposed framework;Thai District Agricultural Officers perceived the proposed seven phases as important steps in developing extension programs. Generally, no significant differences were found in the perceptions toward three selected aspects of program development by variables; however, significant differences were found in regard to years of service, highest education level, and major area of study with respect to one aspect of coordination, type of people involved in program development, and one factor about how program should be developed. Findings suggested a certain program development process with nine procedural steps, feasible to be adopted as a framework for extension program development: determining broad objectives for program development, establishing a planning group, identifying needs, setting program priorities, developing program objectives, developing plan of work, implementing program, evaluating program, and reporting program values.