Several sinkholes occurred in an urbanized development in Kuwait. To identify the causes and determine treatment measures, the properties of the deep sub-soil and bedrock were investigated through a detailed multi-discipline research program consisted of topographic, geological/geotechnical, and geophysical investigations. The results revealed that the geological profile was made of 35–40 m thick sandy overburden soil overlying unconformable Karst limestone bedrock. The cause of these sinkholes was attributed to the collapse of the roof of the Karst cavities and the subsequent raveling of the overburden soil cover. Accordingly, treatment measures were designed and successfully applied which included cavity filling with a sand-cement grout mix and also fracture filling with a cement grout.