This Chapter deals with a compilation of published works in the frame of the applications of the GPR for humanitarian assistance and security. The fields of application, in which the technique has experienced more advances, are the detection of mines and unexploded ordnances, as well as the location of underground spaces. Different types of defensive constructions were built throughout history to protect people from natural catastrophes, aerial bombardments and other attacks. Moreover, the use of the GPR technology in rescue operations is considered by including the main contributions in locating human remains or living victims in disaster areas. An overview of the main GPR works in humanitarian missions and their results are therefore mentioned. Specific systems, methodologies and processing algorithms developed in these applications are also analysed. As result, the method has shown significantly benefits when compared to other traditional searching methods.