We describe the postcranial anatomy of the Miocene puma-sized ailurid Simocyon batalleri, discussing some aspects of its biomechanics and inferring a probable life style. The postcranial anatomy of S. batalleri was previously unknown due the fragmentary nature of its fossil record, and most of the available fossils corresponded to cranial and dental material. With the discovery of a rich sample from the Late Miocene natural trap of Batallones-1, to the south of Madrid (Spain), including the remains of at least two individuals of S. batalleri, it is possible to study for the first time the anatomy of the cervical and lumbar vertebrae, complete forelimb and partial hind limb. The morphology of the forelimb, the lumbar region and the unexpected presence of a false-thumb are strongly suggestive of arboreal capabilities. Such locomotor abilities are consistent with a palaeobiological model of a generalized carnivore that foraged mainly on the ground but could readily climb to trees for safety if faced with the threat of larger competing carnivores. © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152, 593–621.