A descriptive type of research was conducted to study the Cooperative Extension Service in the United States with implications for the Agricultural Extension Program in Sri Lanka. The Commonwealth of Virginia's Cooperative Extension Service was selected for detailed study and information was collected through literature reviews and personal interviews. Based on the writer's experience and available materials, information concerned with the Agricultural Extension Program in Sri Lanka was presented. The information on organizational structure and operation of the cooperative agricultural extension program in Virginia, including the history of agricultural extension programs in the United States; cooperative extension work at Federal, state and county levels; responsibilities of extension personnel; program planning and evaluation; flow of information and teaching methods; staff development; and 4-H activities were collected and compared with similar aspects of the agricultural extension program in Sri Lanka. The comparison of the Cooperative Extension Service in the United States and the Agricultural Extension Program in Sri Lanka shows both differences and commonalities. Basic functions and the general objectives of both extension programs are almost the same, but there are differences between the two extension programs in organizational structure, subject matter coverage, approach to the clientele, procedures of program planning and implementation, staff development and in 4-H activities. Based on the findings of this study, the following most important conclusions were drawn: (1) a lack of formal functional relationship between the Agricultural Extension Service and the higher educational institutes has limited the use of personnel and resources available in the institutes; (2) the lack of job descriptions for agricultural extension workers leads to confusion of their duties and responsibilities; (3) the Agricultural Extension Service in Sri Lanka has not used local clientele committees during the program development process; (4) the village level extension workers do not have input in the preparation and implementation of the programs at the local level; (5) an evaluation unit or commitment for evaluation is neglected in the organizational structure of the Agricultural Extension Service in Sri Lanka; (6) the demonstration method of teaching has been overlooked and is used too infrequently in agricultural extension education activities; (7) technical assistance provided by extension workers is limited to agricultural production; and (8) young farmers program activities have been neglected for many years. Based on the selected conclusions of this study, the selected recommendations were made to help strengthen the Agricultural Extension Service in Sri Lanka: 1. that a formal functional relationship be established between the Agricultural Extension Service and the higher educational institutes; 2. that the duties and responsibilities of extension workers at the various levels be defined; 3. that advisory committees be organized at each hierarchy level of the organizational structure of the Agricultural Extension Service; 4. that agricultural extension programs be developed and implemented at local levels; 5. that an evaluation unit be created as a part of the Agricultural Extension Division; 6. that the demonstration technique be used as a primary teaching method; 7. that the competency level of extension personnel be improved through a systematic and planned preservice and in-service preparation programs; and 8. that village level extension workers organize young farmers clubs in each of their ranges. / Master of Science