Using qualitative theory combined with quantum chemical calculations, we came up with key points that help to discern between regular 2D-aromaticity, albeit in a 3D molecular structure, and true 3D-aromaticity in three-dimensional -conjugated (cage) (macro)molecules. Our study revealed that compounds 1 6+ and 2 (and 3) should not be labelled as, respectively, 3D aromatic and bicycloaromatic. The basic prerequisite for 3D-aromaticity, besides 6n + 2 -electron counts and high -electron delocalization, is a highly symmetric structure with at least triply degenerate MOs, features that do not exist in 1 6+ (also not in approximate sense). Yet, there are clear limitations for tetrahedral and cubic cage compounds that formally fulfill the 3Daromaticity requirements because there are negligible differences in electron delocalization between these cage compounds and near-tetrahedral or near-cubic compounds that have electron counts that deviate from 6n + 2. Hence, there seems to be a size limitation for 3Daromaticity, similar as has been observed earlier for spherical aromaticity. Likewise, the main features of bicycloaromatic species do not exist in 2 and 3.