In this exposition of the problems associated with writing business history three conditioning factors have been kept in mind. The paper is specifically limited to problems in the collaborative writing of business history; by definition, problems peculiar to the writing of the history of a small firm by one person are excluded. Only by collaboration can a satisfactory history of the large integrated unit be written. In the second place, the analysis herein is confined to the more important problems encountered in producing the history of a large business unit. Obviously it would be impossible to discuss in a short paper the whole range of problems which have been met, though not forgotten or ignored. Thirdly, the kind of business history I am talking about is a comprehensive analysis of the policy and management of the firm, not merely a superficial sketch of its corporate history or a survey of either its accomplishments or shortcomings.