In the infant the region lateral to the sella turcica which is traditionally termed the ‘cavernous sinus’ is composed of 3 individual compartments. The aim of this study was to demonstrate a similar compartmentation of the adult cavernous sinus and to identify and quantify the adipose bodies which are located within the compartments. The region of the cavernous sinus in 136 adults was analysed by microdissection and histology. We demonstrate that in 66% of the cavernous sinus in adults is composed of at least 2 compartments and in 22% it is made up of 3. Assimilating the renaming in infants we termed the compartments ‘pterygopalatine’, ‘orbital’ and ‘lateral sellar’. The pterygopalatine and orbital compartments are connected with extracranial tissue spaces via the superior orbital fissure and contain characteristic adipose bodies. Exact topographic descriptions and measurements of the compartments and their adipose bodies are provided. Our study clearly defines compartmentation of the adult parasellar space in most individuals and thus changes the anatomical view of this space. The direct connection of 2 of these compartments with extracranial tissue spaces and the measurements of their adipose bodies are of interest for surgeons and neuroradiologists.