This paper examines the performance of World Economic Outlook (WEO) growth forecasts for 2004-17. Short-term real GDP growth forecasts over that period exhibit little bias, and their accuracy is broadly similar to those of Consensus Economics forecasts. By contrast, two- to five-year ahead WEO growth forecasts in 2004-17 tend to be upward biased, and in up to half of countries less accurate than a naïve forecast given by the average growth rate in the recent past. The analysis suggests that a more efficient use of available information on internal and external factors—such as the estimated output gap, projected terms of trade, and the growth forecasts of major trading partners—can improve the accuracy of some economies’ growth forecasts.