This study attempts to apply the agency theory in the context of Vietnam by analyzing the nature and causes of information transparency problem in Vietnamese enterprises, particularly the listed ones. We consider that the nature of this problem come from the contradictory interests between principal and agent; its main cause is the asymmetric information between the parties involved, which is favored in the context of separation between the business ownership (of principal) and control (of agent). Profiting this lack of information transparency, the agents shall show their opportunism in seeking their self-interest, thus causing short-term damage in profit and long-term damage in value of the enterprise. To solve this problem, it is necessary that all parties should participate to the management and control of the enterprise on the basis of faithfulness and co-operation.