This fifth edition of the "Guidelines for Surveillance of Drug Resistance in Tuberculosis" is an updated version of earlier editions published in 1994, 1997, 2003 and 2009. The document takes into account recent advancements in laboratory diagnostics and subsequent WHO guidance.The aim of this document is to assist national tuberculosis control programs (NTPs) in developing the strongest possible mechanisms of surveillance, starting from periodic country-specific surveys of sampled patients with an ultimate goal of establishing routine continuous surveillance systems based on systematic drug susceptibility testing (DST). Although mechanisms for carrying out surveillance vary from country to country, these guidelines promote certain standardized criteria for surveillance within the Global Project to ensure that results are comparable between participating countries, as well as within countries over time.The target audience of this document is the NTP and, in particular, a coordination team for surveillance ideally composed of the NTP manager, laboratory specialist, logistics specialist, epidemiologist, and statistician.This document is divided into three parts. Part I describes the principles of the Global Project that should be considered fundamental to both continuous surveillance systems and surveys. Part II describes the steps needed to plan and implement a survey in order to determine the burden of MDR-TB in a given area, as well as manage and interpret the collected data. Part III describes an approach to monitoring trends in drug resistance over time. This section is relevant to countries for which baseline MDR-TB burden data already exist from surveys.