The crystal structure of the acetone solvate of pentaphenylethane (C32H26 · 1/2 C3H6O; monoclinic, a = 8.625, b = 16.587, c = 16.961 Å, β = 95.75°, space group P21/c, Z = 4) has been determined by X‐ray analysis. The structure was solved by direct methods and refined to a final R of 0.056. The central ethane bond has a length of 1.612 (3) Å. The cavity enclosing the solvent retains the inversion centre in the crystal: as a consequence, a two‐fold disordered orientation was observed for the acetone molecule. The rotational orientation of the methyl groups was found to be staggered with respect to the C, O‐bond.