This thesis explores how informal sector gold mining affects land development processes in the Brazilian Amazon. The 1987-1990 invasion of the Yanomami Indian reserve, in the state of Roraima, by 40,000 wildcat gold miners provides the context for research. Having analysed the macro-economic and political factors that sparked the gold rush, consideration is given to its impact on the land-uses in the state. Land-use change is analysed by looking at how different rural producers and urban dwellers adapted their management techniques and livelihood strategies to the opportunities arising in the mineral sector. Fieldwork in Roraima was undertaken over a 16 month period between November 1990 and March 1992. Quantitative data was collected on the rates at which different groups of land users participated in the gold rush, while subsequent recorded interviews provided qualitative information on their motives for involvement and how they incorporated mining within their other activities. A large proportion of local smallholders went gold mining in order to supplement their agricultural incomes. Understanding the household economics and risk aversion strategies associated with smallholder migration to the gold fields raises interesting questions concerning the management of the gold rush through appropriate agricultural policies. While this provides an insight into the geography of the labour movements associated with the gold rush, a detailed study of the relationship between informal sector mining and ranching sheds light on the capital flows linked to the mineral boom. As ranchers invested in the gold fields and successful miners bought ranches, changing circumstances in the mining economy came to influence management practices in the beef production sector. The implications that this has on deforestation and land conflict throughout the Brazilian Amazon are discussed. In this way, the mining boom is seen to influence people and places which are distant from the gold fields themselves. This is clearly apparent in the case of Roraima's riverine dwellers and Macuxi Indians. Even though these groups had minimal participation in the gold rush, their lives were profoundly altered by the economic and political changes that it provoked.