This special issue of Near Surface Geophysics on « advanced ground-penetrating radar » is composed of 10 papers initially presented at the 7th International Workshop on Advanced Ground-Penetrating Radar (IWAGPR2013), which was held in Nantes, France, from 2-5 July 2013. This workshop was co-organized by the Institut Français des Sciences et Technologies (Ifsttar), the Centre d'étude et d'expertise sur les risques, l'environnement, la mobilité et l'aménagement (Cerema, DTer Ouest) from the Ministry of Ecology, Sustainable Development and Energy, and the Institut d'Electronique et de Télécommunication de Rennes (IETR) from Nantes University. About 50 presentations were given in eight oral sessions and one poster session, including two invited presentations given by L. Pajewski from Roma Tre University and D.J. Daniels and E. Utsi from the EuroGPR association. The topics covered a wide spectrum including Geological applications, Structures and Pavement characterisation, Buried Object detection, Antenna design, Modelling, Processing and Inversion/Imaging. The IWAGPR workshop is part of a biennal series of international scientific symposia devoted to the advancements in ground-penetrating radar (GPR) techniques and applications. Facing challenges such as natural hazards or aging infrastructures, GPR is a geophysical, non-destructive testing technique that has several assets compared to other techniques which enable a wide variety of applications ranging from sub-surface imaging and characterisation to investigation of transport infrastructures and buildings. This IWAGPR event was a fruitful opportunity where about 100 scientists from academia, government and industry, coming from 22 countries worldwide, discussed, promoted and exchanged information about the current developments and applications on advanced GPR. Several authors who contributed to the workshop were invited to submit full-length papers describing their current research findings. Three papers within this special issue cover the topics of electromagnetic propagation, scattering and inversion. Two papers investigate the diffraction curve and topographic effect on the migration process and one paper is focused on ultra wideband (UWB) antenna design. The final four papers describe the evaluation of civil engineering structures.