Three-photon absorption (3PA) and subsequently induced optical limiting behavior of several stilbazolium derivatives were investigated by using a mode-locked/Q-switched Nd:YAG pulse with a duration of 35 ps and a repetition of 10 Hz at 1064 nm. The measured molecular 3PA cross-sections are in the order 10(-78)-10(-76), cm(6) s(2) at the intensity levels of 0-55 GW/cm(2). It is observed that the 3PA cross-section as well as the optical limiting effect can be enhanced by increasing strength of electron-acceptor units of stilbazolium derivatives. (C) 2002 Elsevier Science B.V. All rights reserved.