Fluorescence, fluorescence excitation and absorption spectra of picene have been measured in the vapor phase. It is shown that picene vapor exhibits weak fluorescence from the S-2(pi, pi*) state in addition to strong S-1(pi, pi*) fluorescence. The S-2/S-1 fluorescence yield ratio is evaluated to be approximately 1.3 x 10(-2) following the excitation into the S-3 state. It is shown that the relative S-2 fluorescence quantum yield increases with increasing excitation energy, while the S-1 fluorescence yield is nearly invariant. Mechanism of the appearance of the S-2 fluorescence of picene vapor is discussed. (c) 2013 Elsevier B.V. All rights reserved.