Demographic interest in population and environment has grown in recent decades. One of the most prominent research areas in this tradition addresses the impact of population on land use and land cover change. Building on this tradition, we examine the effects of household demographic composition on land use and land cover on small farms in two study areas in the Brazilian Amazon. Fixed effects regression models of used area and forested area show few consistent effects of changes in household demography on land use and land cover change. Effects are inconsistent with the household life cycle model that currently dominates the literature on household demographic effects in frontiers. Changes in the number of children and women, particularly young women, have the most significant effects on land use and land cover change. We conclude by arguing that households strategically access cash for investment in agriculture and that specific strategies are determined by economic and institutional context.283163185