The 37th International Symposium on the Scientific Basis for Nuclear Waste Management (Materials Research Society Symposium Proceedings Volume 1665) was held in Barcelona (Catalonia, Spain), September 30-October 3, 2013. The symposium was officially opened by Dr Antoni Gurgui, commissioner of Consejo Seguridad Nuclear (Nuclear Safety Council) in Spain. About 80 attendees from 12 countries listened to 51 presentations and discussed 29 posters during the three and a half days of scientific sessions. The symposium covered the following topics: national and international programs; performance assessment/geological disposal; radionuclide solubility, speciation, sorption and migration; corrosion studies of zircaloy, container and carbon steel; high-level waste; and ceramic and advanced materials.