Rapid urbanization together with policy ineffectiveness in controlling urban growth is often associated to soil and land degradation in both the developing and developed world. The present study analyses the relationship between urban expansion and soil degradation in an arid Mediterranean region (Attica, Greece) where the compact settlement pattern has been replaced by low-density urban development. The study area is one of the most densely populated areas in the Mediterranean basin that has experienced an impressive growth in population during the last 60 yr. Low-density, dispersed urban settlements developed during the last decade (2000–2010) occupy primarily land at medium-low soil quality. However, the overall quality conditions of vegetation, climate and soil assessed by our study shows that urban expansion consumed high-quality land previously classified as non-vulnerable to desertification. By contrast, compact urban settlements have consumed land of intermediate or even high soil quality, but experience poor climatic and vegetation conditions that are classified as highly vulnerable to desertification. Regional planning should incorporate multi-dimensional indicators of soil, climate and vegetation quality to evaluate the environmental impact of urban expansion.