The birth of traditional cooperatives goes back to the origin of mankind. In Ethiopia, there are a number of such traditional organizations to solve the common problems of their members. However, the birth of modern cooperative is a recent development in the history of Ethiopia. Following its introduction, the cooperative movement was exploited for political purposes and its principles and values were wrongly implemented. Even though many efforts were made to restructure the cooperative development of the country, participation of members in their cooperative society is still very low. This work was thus undertaken give some light on the impact of members'' awareness on the cooperative principles, values, bylaws, benefits, and cooperative society''s proclamation and its impact on their participation in the business and decision making activities of their cooperatives. The findings of the work revealed high gap of members'' awareness on cooperative ideas and the serious impact of this on participation in their cooperative activities.