The news of America’s housing crisis, and the implosion of the sub-prime mortgage lending industry has spread throughout the globe. Still, little is known even amongst Americans about where foreclosures themselves are concentrated, or the degree to which foreclosed properties are being left vacant and succumbing to decay. Focusing on Philadelphia, this research combines Sheriff’s Department data on foreclosed properties with property title searches and demographic data to construct a precise demographic description of the neighborhoods where foreclosure occurs most abundantly. Common amongst these communities is the predominance of African Americans, accompanied by sizeable minority populations of Whites and moderately strong property values between $50,000 and $90,000. While few foreclosed properties are succumbing to abandonment within these communities, thousands are being left vacant for short term periods of nine to ten months. Meanwhile, adjustable rate mortgages continue to reset in greater numbers, and property values in Philadelphia are beginning to fall. If decisive action is not taken to encourage residents to purchase and occupy foreclosed properties, much of the housing stock within these neighborhoods is at risk of deterioration.