Internal audit is a function to ensure independence and objectivity, and plays a role as an advisory entity, improve the value and perfect the organization's activities. Internal audit also contributes to the achievement of the organization's objectives by adopting a systematic and rigorous approach to evaluate and improve the effectiveness of the risk management processes and control and administration procedures. Survey of the current internal audit in private sector in Vietnam is conducted in different types of businesses, including commercial banks, listed joint stock companies, state-owned enterprises, and equitized state-owned enterprises, foreign enterprises, and some other private enterprises. The purpose of the paper is to provide (a) an assessment of the current internal audit in the private sector in Vietnam, (b) an overview of differences between the current internal audit and best practices for internal audit, (c) analysis of necessity, and (d) some initial recommendations for internal audit in private sector & banking sector in Vietnam.