This study investigated the influence of population growth on land-use/land-cover changes observed in north-eastern Wollega, Ethiopia between 1972 and 2005. A knowledge-base that will support sound and informed decision-making on sustainable resource management is provided. The changes in land-use/land-cover observed in this region are linked to rainfall and availability of arable land. These two factors combined have encouraged the migration of farmers from relatively less productive areas of the north and centre of the country. To quantify impacts, the study used a combination of land-use/land-cover detection techniques based on time series image processing, assessment of population dynamics and linear regression models. Results indicated that since the 1970s, cropland and settlement areas expanded at the expense of land formerly occupied by forest, shrub and grassland. The regression analyses showed that such changes were associated (P<0.05) with population growth, which averaged 3% per year. The decline in areas occupied by grassland was not correlated with population growth but rather with changes in land-use. Other factors that significantly influenced land-use/land-cover changes were: farming system, government policies and land tenure system, and lack of technology choices. Maintaining the necessary resource-base is a requirement to ensure the long-term sustainability of the region. Therefore, appropriate land management policies need to be developed and implemented at the national level, however, measures should have regional relevance. Additional measures such as promotion of policies that support the process of sustainable intensification of Ethiopian agriculture coupled with effective extension effort, and greater diversification of the source of income for the rural communities are also suggested.