The wavelength-dependent mass-selected ion signals produced by supersonic-cooled ferrocene irradiated with nanosecond laser pulses in the region of the 3d(z)(2) --> R4p(x,y) transition (40 000-42 000 cm(-1)) have been investigated. Surprisingly, in a one-color multiphoton experiment, conditions have been found for the formation of intact molecular ions (C5H5)(2)Fe+ as the only ionic product. Neutral iron atoms are generated, however, in large amounts under these conditions by the photodissociation of the ferrocene molecules. Multiphoton ionization of the Fe atoms by the second UV laser makes it possible to reveal a resolved vibronic structure of the ferrocene Rydberg transition. The two-color multiphoton dissociation/multiphoton ionization spectrum shows a 0(0)(0) peak at 41 090 cm(-1) and a 4(0)(1) component at 41 410 cm(-1) demonstrating better resolution than the one-photon absorption spectrum measured in a static cell at elevated temperature. The distance between the vibronic components corresponds to the symmetric metal-ligand stretch in the Rydberg state. The two-color mass spectrum is changed dramatically when the second laser operates in the 17 500-cm(-1) region. In this case, the excited states populated by the first laser are ionized efficiently by the second one, and the intensity of the molecular ion signal increases significantly. The REMPI excitation spectra measured at the masses of (C5H5)(2)Fe+ and fragment ions agree very well with that derived from the ionization of neutral iron atoms and reveal the same vibronic structure of the 3d(z)(2) --> R4p(x,y) transition in the ferrocene molecule.