Collapsible soils are present in arid and semi-arid regions in an unsaturated state and are considered to be one of the problematic soils that face engineering and geotechnical challenges. They are regarded as sensitive soils where their structure and engineering properties change upon wetting (leaching or soaking). The wetting leads to a break in the bonds between the soil particles (salts or clay) and a decrease in the suction power that binds the soil particles together. Large settlement occurs and thus causing problems for the buildings and facilities constructed on them. Recognizing the properties and characteristics of collapsible soils is very important in order to know how to deal with them to avoid unnecessary financial losses and problems. This paper gives an overview of collapsible soils behavior and prediction in many aspects.