In 2008, the Centers for Disease Control and Prevention (CDC) and the World Health Organization developed the Global Adult Tobacco Survey (GATS), an instrument to monitor global tobacco use and measure indicators of tobacco control. GATS, a nationally representative household survey of persons aged 15 years or older, was conducted for the first time during 2008–2010 in 14 low- and middle-income countries. In each country, GATS used a standard core questionnaire, sample design, and procedures for data collection and management and, as needed, added country-specific questions that were reviewed and approved by international experts. The core questionnaire included questions about various characteristics of the respondents, their tobacco use (smoking and smokeless), and a wide range of tobacco-related topics (cessation; secondhand smoke; economics; media; and knowledge, attitudes, and perceptions). In each country, a multistage cluster sample design was used, with households selected proportionate to the size of the population. Households were chosen randomly within a primary or secondary sampling unit, and one respondent was selected at random from each household to participate in the survey. Interviewers administered the survey in the country’s local language(s) using handheld electronic data collection devices. Interviews were conducted privately, and same-sex interviewers were used in countries where mixed-sex interviews would be culturally inappropriate. All 14 countries completed the survey during 2008–2010. In each country, the ministry of health was the lead coordinating agency for GATS, and the survey was implemented by national statistical organizations or surveillance institutes. This article describes the background and rationale for GATS and includes a comprehensive description of the survey methods and protocol.