Deglaciation processes in the upper Gállego Valley, central-southern Pyrenees, were studied using geomorphological mapping and 36 Cl cosmogenic dating of moraine and rock glacier boulders, as well as polished bedrock. Although the precise position of the Gállego Glacier during the global last glacial maximum is not known, there is evidence that ice tongues retreated to the headwaters, which caused subdivision of the main glacier into a number of individual glaciers prior to 17ka. A range of ages (16 to 11ka) was found among three tributary valleys within the general trend of deglaciation. The retreat rate to cirque was estimated to be relatively rapid (approximately 5km per ka). The mapped glacial sedimentology and geomorphology appears to support the occurrence of multiple minor advances and retreats, or periods of stasis during the late deglaciation. Geomorphological and geological differences among the tributary valleys, and error estimates associated with the results obtained, prevented unambiguous correlations of the advances with the late Pleistocene cold periods. During the latter advances, small glaciers and rock glaciers developed close to the cirque headwalls, and co-occurred under the same climatic conditions. No evidence for Holocene re-advance was found for any of the three tributary valleys. © 2015 University of Washington. ; This study was performed with the support of the projects CGL2006-11619/HID, CGL2011-27753-C02-01 and CGL2012-35858, funded by the Spanish Ministry of Economy and Competitiveness. The research group on Geomorphology and Global Change was financed by the Aragón Government and the European Social Found (ESF-FSE) (E68). The authors acknowledge Dr David Fink, Dr Magali Delmas and an anonymous reviewer for their valuable comments on the manuscript. We also particularly thank Dr Irene Schimmelpfennig, whose collaboration was essential to the study.