The characterization of the first portable artistic depictions in Cantabrian Spain is crucial for comprehension of the symbolic development of Neandertals and Homo sapiens in the context of the passage from the Middle to the Upper Paleolithic. However, despite the importance of these first graphic representations, their study has tended to lack the application of suitable methodologies to be able to discriminate between graphic activity and other kind of alterations (use-wear, taphonomic, or post-depositional). The present study has examined a significant sample of Middle and Upper Paleolithic lithic and osseous objects from Cantabrian Spain that have been cited as evidence of graphic activity in the literature. The contexts in which the objects were found have been considered, and the objects have been analyzed through the microscopic observation of the marks to distinguish between incisions, pecking, and engraving made for a non-functional purpose (graphic activity) and those generated by diverse functional actions or taphonomic processes (cutmarks, trampling, root marks, percussion scars, and use-wear). The results show that some regional Middle Paleolithic osseous objects display incisions that are neither functional nor taphonomic and whose characteristics are similar to graphic evidence attributed to Neandertals in Europe and the Near East. In turn, the first portable art produced by Homo sapiens in the Cantabrian Spain seems to be limited mostly to linear signs, and no figurative representation can be recognized until the Gravettian. This appears to indicate a particular idiosyncrasy of the region in the Early Upper Paleolithic, which, in comparison with other regions such as south-west France and the Swabian Jura, shows a later and less abundant production of portable art.