This article offers a selective guide to the OECD's expanded work on taxation over the last decade. The article first gives some of the reasons for the increase in the OECD's tax activities and describes the OECD's new tax role in the world outside the OECD countries. The article then considers the main activities of the five working parties of the Committee on Fiscal Affairs. The article also discusses the work done largely outside the working parties and describes the OECD's recent work on tax reform and tax policy. The article concludes with some personal observations.