The focus of this study is on voluntary membership of farmers in agricultural cooperatives. Communication channels and personal motives of farmers are investigated in an effort to understand the problems hindering the agricultural cooperation movement. The main purpose of this study is to critique the traditional diffusion model in its application to cooperative membership in Saudi Arabia. Suggestions are made to expand the traditional model beyond utilitarian considerations to consider cooperation as a moral obligation. This comes out of a deontological perspective where cultural (moral) conditions are combined with perceived individual benefits for understanding how farmers decide on whether or not to join agricultural cooperatives;The research was conducted in Qassim, an agricultural area located in the Central Region of Saudi Arabia. Face-to-face interviews were conducted with a sample of 219 farmers during summer 1991. Results of the discriminant analysis show that accepting the idea of becoming an agricultural cooperative member by respondents was impacted by the same factors usually influencing adoption of most agricultural innovations. Members of the cooperative, however, were not only more educated and had larger farms, higher farm incomes, and more knowledge about cooperatives. They also provided more assistance to other farmers and viewed cooperation with others as an important matter. Implications of the findings are drawn. Finally, limitations of the study and suggestions for further research are discussed.