The recent emergence of concern for sustainability, or sustainable development, has lead to a renewed interest in the adequacy of national income accounts for monitoring economic performance. It has been argued that natural resource accounting is needed, and that national income accounting conventions need modifying. The paper reviews this background and argument, and distinguishes several types of natural resource accounting. It is noted that adjustment of measures of national income requires valuation, and that with respect to sustainability objectives market and surrogate market prices are inappropriate. It is argued that the pursuit of sustainability requires modelling rather than historical accounting. Some recent, unofficial, attempts at revising national income data to reflect sustainability concerns are critically reviewed. Finally, data requirements for ecological sustainability are considered.