Real estate tax delinquency is emerging as a major component of the urban fiscal crisis, affecting cities as diverse as Houston, Pittsburgh, New York, and Atlanta. A large and increasing proportion of uncollected taxes wreak havoc with any city's budgetary and planning process. Even more important, a growing rate of tax delinquency is symptomatic of fundamental changes in the role of the city in the American political economy. This study examines tax delinquency as a component of the flight of private capital from the central city. Delinquency trends in forty-eight cities over a twenty-five-year period are analyzed to set the national context, and an in-depth case study examines the problem at the neighborhood level. Interviews with 158 delinquent property owners uncover the reasoning behind the delinquency decision. Public policy options are evaluated in light of the severe practical and ideological limitations on public response to private disinvestment. Lake provides a brief survey of the available literature on tax delinquency, at both city-wide and neighborhood scales, focusing on the change in emphasis over time from a concern with administrative remedies to a search for systemic solutions. An overview of housing and demographic trends affecting the City of Pittsburgh in recent years is examined in depth. Lake surveys property owners to delve into the behavior of delinquent owners and concludes with discussing the City's role and implications for policy. Improving the situation is considered in terms of avoiding the conditions that lead to delinquency, and improving the city's capability of administering parcels acquired through tax-taking mechanisms.