The structure of the 1:2 co-crystalline adduct C8H16N4·2C6H5BrO, (I), from the solid-state reaction of 1,3,6,8-tetra­aza­tri­cyclo­[4.4.1.13,8]dodecane (TATD) and 4-bromo­phenol, has been determined. The asymmetric unit of the title co-crystalline adduct comprises a half mol­ecule of aminal cage polyamine plus a 4-bromo­phenol mol­ecule. A twofold rotation axis generates the other half of the adduct. The primary inter-species association in the title compound is through two inter­molecular O—H⋯N hydrogen bonds. In the crystal, the adducts are linked by weak non-conventional C—H⋯O and C—H⋯Br hydrogen bonds, giving a two-dimensional supra­molecular structure parallel to the bc plane.