Abstract This article is concerned with the change in objectives and the expansion of activities described as internal auditing. So sweeping has been this change that current definitions of internal auditing bear little resemblance to those in vogue ten or fifteen years ago. Internal auditing fulfils an economic need quite separate and distinct from the services rendered by independent public accountants. Internal auditing is now regarded as an appraisal activity, employed to aid the top management of a large corporation in the efficient administration of the enterprise. It is characterized as a staff function, independent of accounting and operating processes, and responsible to a member of top management, most commonly the controller. Regardless of the size of the client's business, the certified public accountant must always bear a major responsibility to stockholders, creditors, bankers, government and to the general public which reads the financial reports he certifies. In fulfilling the strenuous requirements of his profession, he is automatically barred from performing the full time continuous research into the detailed operations of a single corporation which management needs in order to do its job with maximum effectiveness.