Pyrogallol[4]arenes self-assemble to form stable hydrogen-bonded nanocapsules that have many unique properties making them potentially suitable for diverse applications, such as molecular transporters and nanoreactors. However, little is known about the host–guest behaviour of these materials. Utilizing nanoenvironment-dependent properties of the fluorescent reporter molecule, pyrene butanol (PBOH), the encapsulating abilities of the hexameric C-hexylpyrogallol[4]arene (PgC₆) nanocages are further explored. Solution-state, spectroscopic and spectrofluorometric investigations and solid-state, single-crystal X-ray diffraction studies are in agreement and indicate an ordered inner phase. Up to two PBOH guest molecules are sequestered within the nanocapsule along with encapsulation solvent. The nature of the PBOH–PgC₆ complex is found to change with time, as indicated by fluorophore leaching. These research findings provide additional insight into the encapsulation capabilities of PgC_n nanocapsules.