Interorganizational cooperation or conflict among agricultural support organizations affects the efforts of agricultural development. Several sociological theories were used to provide a backdrop for understanding interorganizational relationships among agricultural support organizations. Data were collected from face-to-face interviews with 127 respondents from 74 organizations in Khon Kaen province, Thailand. LISREL was used to evaluate the theoretical model and to test the hypotheses with two groups of organizations. Data analysis shows that frequency of contact did not significantly contribute to the explained variation of both cooperation and conflict. Perceived interdependence was found to be associated with cooperation whereas perceived competition was correlated with both cooperation and conflict. Domain consensus appears to be less important in explaining the variation of cooperation and conflict. Goal similarity was negatively related to both cooperation and conflict. Local dependency significantly correlated with domain consensus, perceived interdependence, and perceived competition in Group 1, but not in Group 2 organizations. Awareness contributed significantly to the explained variation of perceived interdependence, perceived competition, but not to domain consensus in both groups. The theoretical model was evaluated by several procedures. The evaluation indicated that the proposed model did not fit the data.