This study create a measure of co-operative governance in the form of co-operative governance index (CO-opGI) based on a dataset from 78 credit co-operatives in Malaysia. (CO-opGI) is a composite measure of 20 indicators derived from experts' opinion, survey and annual reports under the categories of four co-operative governance mechanism: board effectiveness, member active participation, internal audit committee’s efficiency and management’s efficiency. there are five stages of process in constructing the (CO-opGI):(i) indicators identification, (ii) measurement identification,(iii) measurement standardization, (iv) measurement weighting and (v) measurement conversion into indices, This index is used as a proxy measure of the level of co-operative governance organs (member, board, internal audit committee and management) with CO-opGI). The result shows that size of management and size of internal audit committee relate positively with CO-opGI). Cluster analysis groups the 78 co-operatives into five groups according to their levels of CO-opGI) and finds that size, competency and compliance of internal audit committee are significantly different across the five groups of CO-opGI) in which the bery high CO-opGI) groups shows the highest score, The tests show that board communication, member active participation and management efficiency differ significantly between CO-opGI) groups. The result imply that CO-opGI) is valid and reliable in measuring corporate governance in co-operatives.