Updates Dynamics of Household Land Use and Economic Welfare on the Amazon Frontier, 1996-2005, Rondonia, Brazil, examines household land use and economic welfare of residents living in the highly deforested Amazon basin region of southern Brazil. This release represents the 4th round of data collection which includes primary data from household panel surveys in the core study area, combined with several other sources of data, including cadastral maps matched with satellite imagery to quantify land cover change, spatial data on biophysical factors, markets, and public infrastructure, and secondary data from official sources (such as agricultural census data). Interviews were conducted with respondents residing in the Ouro Preto do Oeste region of the Brazilian state of Rondonia. Survey questions focused on respondent ownership of land lots, years of residency on the lots, property sales, physical characteristics of lots and dwellings, types and quantity of livestock and crops, and use of fertilizers, pesticides, and herbicides. Several questions asked respondents whether they owned various durables, including vehicles, household appliances, tools, and farm equipment. Demographic information includes age of respondent and other household occupants, household size, migration, and education level, as well as information on household income, assets, pensions, and cost of living.