This article presents estimates of six dimensions of governance for 199 countries and territories from 1996 to 2002. The indicators are based on several hundred individual variables from 25 data sources constructed by 18 organizations, covering aspects such as voice and accountability, political stability, government effectiveness, regulatory quality, rule of law, and control of corruption. An unobserved-components model is used to construct aggregate governance indicators for each dimension in each period. The article discusses methodological issues, including potential biases and the interpretation of the data, given the estimated margins of error. It also examines the construction and use of the governance indicators, the importance of ideological biases in expert assessments of corruption, and the implications for aid allocation rules. The data and a web-based graphical interface are available online. The study highlights the benefits of combining related indicators into aggregate scores, which provide more precise measures of governance and allow for comparisons across a broader set of countries. However, it also notes that the margins of error remain large, suggesting caution in interpreting changes over time.This article presents estimates of six dimensions of governance for 199 countries and territories from 1996 to 2002. The indicators are based on several hundred individual variables from 25 data sources constructed by 18 organizations, covering aspects such as voice and accountability, political stability, government effectiveness, regulatory quality, rule of law, and control of corruption. An unobserved-components model is used to construct aggregate governance indicators for each dimension in each period. The article discusses methodological issues, including potential biases and the interpretation of the data, given the estimated margins of error. It also examines the construction and use of the governance indicators, the importance of ideological biases in expert assessments of corruption, and the implications for aid allocation rules. The data and a web-based graphical interface are available online. The study highlights the benefits of combining related indicators into aggregate scores, which provide more precise measures of governance and allow for comparisons across a broader set of countries. However, it also notes that the margins of error remain large, suggesting caution in interpreting changes over time.