This dataset comprises cast reconstructions of brain cavity space in 60 extant avian species, derived from X-ray micro computed-tomography scan image stacks. Each reconstruction was made using Materialise Mimics 14.11 to create volumetric models (brain cavity casts) that were then transformed into the polygon mesh stereolithograph (STL) files archived here. Brain cavity cast models are in most cases accompanied by casts of main vascular features (e.g., carotid arteries) and the olfactory nerves (CN I). A data file (Data_TableComma Separated Values) based on values reported in Table 1 of Walsh et al. (2013: doi:10.1371/journal.pone.0067176) is included that records volume values used in the original analysis, and coding of cerebellar flocculus morphology. Full details about this nonGeographicDataset can be found at https://doi.org/10.5285/4e15f483-5b05-409e-acc0-5117fc24e90b