This research work deals with the problem of karst sinkhole collapse occurringin the last few years in Cheria area. This newly revealed phenomenon is of amajor constrain in land use planning and urbanization, it has become necessarytoassess the stability of these underground features before any planningoperation. Laboratory testing and field work were undertaken in order todetermine both intact rock and rock mass properties. All the rock mechanicstesting and measurement were undertaken according to the ISRMrecommendations.It has been found that under imposed loading, the stability of the karst cavitiesdepends on the geo-mechanical parameters (Rock Masse Rating; RMR,Geological Strength Index; GSI, and Young Modulus; E) of the host rock aswell as the depth and dimensions of the gallery. It increases with RMR, GSI, Eand depth and decreases as the cavity becomes wider. Furthermore, thecalculation results show that a ratio (roof thickness to gallery width) of 0.3 andmore indicate, a stable conditions.The results obtained in this work allow identifying and assessing the stability ofunderground karst cavities. The methodology followed in this paper can betaken as a road map in the establishment of a hazard map related to the studiedphenomenon. This map will be a useful tool for the future urban extensionplanning in Cherea area.