The purposes of this study were to identify group characteristics of County Extension Advisory Committees which were related to the effective performance of the committees and to identify the leadership behavior dimensions of County Extension Agent Chairmen which were related to the effective performance of County Extension Advisory Committees. The design of the study included the description of 13 group dimensions of County Extension Advisory Committees, the description of the County Extension Agents' leadership behavior on the dimension of initiation of structure and consideration by County Advisory Committee members, and the evaluation of County Extension Advisory Committees on three functions of effectiveness by the District Supervisor. Two questionnaires were used to collect the data, one to secure the data on the group situation and the other on the leadership behavior dimensions of the County Extension Agent Chairmen. A stratified random sample was secured by selecting five Advisory Committees from each Extension district. Among the conclusions, based on findings, was that the performance of County Extension Advisory Committees was more effective when the County Agent Chairmen were perceived to provide initiation of structure leadership behavior for the Advisory Committees. (author/aj)