Diamondoids are polycyclic saturated hydrocarbons with diamond-like properties that can find application in various fields, especially as scaffolds in nanomaterial design [1]. Functionalization of diamondoids can give access to a plethora of useful derivatives and it is also possible to make diamondoid composites consisting of several diamondoid cage subunits connected with a heteroatom or a functional group. We recently prepared such composites that had an ether linker [2] in order to test their self-assembly capabilities on a material surface. More specifically, we deposited diamondoid ethers on a highly oriented pyrolytic graphite (HOPG) surface and used microscopy (STM) to identify the structural characteristics of the formed monolayers. Note that characterization of on- surface self-assemblies of such bulky cage molecules is challenging due to their non-planar nature. We also conducted a detailed computational analysis that revealed the most favorable on- surface orientations of these rigid molecules and confirmed that their spontaneous self-assembly was governed by London dispersion interactions acting between cage subunits. Moreover, we elucidated that the oxygen atom played an important role in directing the molecules towards the graphite surface (Figure 1), whereas the abundant side C–H contacts between the cages were crucial for the formation of an ordered 2D lattice. Thus, our findings provide one step forward in predicting on-surface behavior of non-aromatic organic compounds and their monolayer properties.