The crystal structure of bis-(2,4-pentanedionato)4-aminopyridinecopper(II) has been refined to an R value of 0.070 from photometric Weissenberg film measurements. The cell is monoclinic with a = 836 ± 3 pm, b = 1475 ± 3 pm, c = 1435 ± 3 pm, β = 112.14 ± 0.20°. The space group is P21/c (No. 14) with four molecules per cell. The density is 1.44 ± 0.01 g cm−3 (measured), 1.442 ± 0.013 g cm−3(calculated). The geometry about each copper atom is approximately that of a tetragonal pyramid, with the copper atom 22 pm above the basal plane. The apex of the pyramid is occupied by an oxygen atom, the heterocyclic nitrogen is in the basal plane, and the 4-amino group is uncoordinated and hydrogen bonded to oxygen in a neighboring molecule.