AbstractInspired by the teaching of Father Arizmendiarrieta, some of his students set up a co-operative in Mondragon, northern Spain, in 1956.Since then other co-operatives have been formed all operating with a common set of rules. The group has its own bank which links the members through a Contract of Association.The movement is dynamic and changes are currently being implemented to take account of economic and technological advances.This is a success story for workers' co-operatives as seen by the increase of worker-members, sales, exports and investments.