Hydroquinone (benzene-1,4-diol or quinol) is reported here to form co-crystals in different ratios with propan-2-ol, N,N-dimethylacetamide (DMA) and N,N-diethylformamide (DEF). Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analysis reveals that more than two-thirds of the close contacts are associated with relatively weak HÁ Á ÁH, CÁ Á ÁH and HÁ Á ÁC interactions. The use of Hirshfeld surfaces in combination with fingerprint plots demonstrates that these weak interactions are important for both local packing and crystal packing. The complexes highlight the way in which electrostatic complementarity to a large extent governs the hydrogen bonding pattern in molecular crystals.Scheme 1