We report on Langmuir-Blodgett (LB) characterization of 1-(N-ethyl-1-sulphonate-4-pyridinio)-2-[N-(n-hexadecyl)pyrrol-2-yl]ethene (C16H33-ESPPE). Surface pressure-area isotherms of spread monolayers were investigated at pure water/air interface; LB films were characterized by means of W-vis and steady state fluorescence spectroscopies. The compound is photobleachable and undergoes a dimerization reaction in monolayer and in solution, the strong absorbing band due to a pi --> pi* transition in the visible region disappears by exposing the compound to visible light. A blue shift of this band in LB films with respect to the solution is attributed to a deck-of-cards packing of the chromophore in the film. The photobleachable absorption band could have potential applications in optical data storage; the molecule could also be very interesting for two-photon pumped (TPP) frequency-upconversion lasing applications.