On the potential of Persistent Scatterer Interferometry for monitoring dikes in the Netherlands R.F. Hanssen and F.J. van Leijen Major flooding disasters like in New Orleans, August 2005, have influenced the hazard likelihood assessments for areas situated below mean local sea level. Large parts of the Netherlands can only exist because of huge infrastructural water defense objects (dikes, dams, storm-surge barriers, etc). Most of the Netherlands' 16 million people live on land reclaimed from the sea, and 70 percent of the gross national product is earned in these vulnerable areas. Failure of these water barriers can have catastrophic humanitarian and socio-economic consequences, with lessons learned from flooding as in Zeeland (1953). More recently, dike failures as in the cities of Wilnis, Terbregge (2003), and Stein (2004), have shown that knowledge of failure mechanisms should be improved, and that the regular inspections of primary and secondary water barriers failed to detect hazardous areas. In this study, we evaluate the potential of Persistent Scatterer Interferometry (PSI) data to identify and monitor potentially weak segments of water barriers in the Netherlands. We analyze 9 stacks (ascending, descending, and various adjacent tracks) of 50-100 scenes each. We identified deformation at dikes due to consolidation, weak subsurface layers, slip of embankments, and structural composition changes.