The crystal structure of the adduct of copper(II) acetate monohydrate and 1-amino-4-aza-9-fluorenone Cu-2(CH3COO)(4)(H2O)(2) . C12H8N2O was determined. The structure is layered; the layers are formed by alternating columns of copper(II) aetate monohydrate complexes and columns of dimers of 1-amino-4-aza-9-fluorenone. The layered structure of the adduct is stabilized by a hydrogen bonding system. Changes in the IR absorption spectra due to the formation of the adduct were discussed.