The popularity of tourism as a component of development strategy in low-income countries is founded in part upon the belief that expansion of this industry will improve income distribution by greatly expanding demand for relatively low-skilled labor. We examine this belief for the case of Thailand, a highly tourism-intensive economy, using a new and specifically-designed applied general equilibrium model. A boom in inbound tourism demand generates foreign exchange and raises household incomes across the board, but worsens their distribution. Tourism sectors are not especially labor-intensive, and the expansion of foreign tourism demand brings about a real appreciation that undermines profitability and reduces employment in tradable sectors, notably agriculture, from which the poor derive a substantial fraction of their income. We examine the robustness of these results with respect to alternative factor market assumptions relevant to the Thai economy.