When a landslide reaches a river valley floor it may develop a landslide dam. If it forms a lake basin, unstable landslide dams can have catastrophic consequences in populated regions. In order to assess the formation and stability of landslide dams, it is important to analyze past damming cases. Landslide dam behavior is not completely understood, even though several authors have tried to describe their formation and evolution by geomorphological analysis. Starting from the study of the characteristics of 300 obstruction cases collected in Italy, some state-of-the-art morphometric indexes are applied and evaluated. The data suggest that landslide velocity is not a good predictor for dam stability assessment, while landslide dam volume and catchment area confirmed to be more useful for this purpose.