Laser irradiation effects on the deposition process (laser-assisted deposition) of 10-(1-pyrenyl)decanoic acid (PyC10) were investigated by measuring in situ fluorescence spectra during deposition. Fluorescence spectra of films prepared by laser-assisted deposition were different from those of normally deposited films and depended upon laser fluence. A difference in the absorption spectrum among these films was also observed. Laser irradiation effects on normally deposited films of PyC10 (irradiation after deposition) were investigated for comparison. On the basis of these results, the high potential of laser-assisted vacuum deposition is discussed.