This article analyses the purpose and scope of Art. 9(1) of the OECD Model and specifically the nature of the transfer pricing adjustments covered by Art. 9(1). After summarizing the historical development of this provision, the article analyses the purpose of Art. 9(1) and examines the relationship between Art. 9(1) and the other articles of the OECD Model, the relationship between Art. 9(1) and domestic tax law, and the adjustments that come under Art. 9(1). The article concludes that Art. 9(1) is concerned only with genuine transfer pricing adjustments and that transactional adjustments are outside its scope.