The 2011 Liberia Malaria Indicator Survey (LMIS) was carried out by the National Malaria Control Program of the Ministry of Health and Social Welfare (MOHSW) in collaboration with the Liberia Institute for Statistics and Geo-Information Services (LISGIS). The government of Liberia provided financial assistance in terms of in-kind contribution of personnel, office space, and logistical support. Financial support for the survey was provided by the United States Agency for International Development (USAID) from President's Malaria Initiative funds through ICF International. ICF International also provided technical assistance, medical supplies, and equipment for the survey through the MEASURE DHS program, which is funded by USAID and is designed to assist developing countries in collecting data on fertility, family planning, and maternal and child health. The opinions expressed in this report are those of the authors and do not necessarily reflect the views of USAID. The 2011 Liberia Malaria Indicator Survey (2011 LMIS) presents the major findings of a survey of a large, nationally representative sample of more than 4,000 households. This survey was conducted from late September 2011 through December 2011. The 2011 LMIS is a follow-up to the 2005 and 2009 LMIS surveys and provides updated estimates of basic demographic and malaria indicators. The primary objective of the 2011 LMIS is to provide current information for policymakers, planners, researchers, and programme managers. Topics include ownership, access, and use of mosquito bednets; coverage of the intermittent preventive malaria treatment program among pregnant women; prompt and effective malaria treatment practices among children under age 5; and malaria-related knowledge, attitudes, and practices in the general population. Additionally, the 2011 LMIS provides population-based prevalence estimates for anemia and malaria among children age 6-59 months.