A novel amphiphilic block copolymer of an ionic acetylene and styrene was prepared. Initiation of the N-methyl-2-ethynylpyridinium trifluoromethanesulfonate (2EPyMeTf) by living anionic polystyryl-Li+ resulted in polystyrene(12)-block-poly(2EPyMeTf)(4). This amphiphilic block copolymer (PSP-A) contains a conjugated and strongly hydrophilic polyacetylene chain attached to a more flexible hydrophobic polystyrene chain. The structure of PS-PA was confirmed by FT-IR, UV-visible, and H-1, C-13, N-14, and F-19 NMR spectroscopy. Gel permeation chromatography (GPC), vapor pressure osmometry (VPO), and viscometry were used to obtain information on the molecular mass and molecular mass distribution. Thermal properties were investigated by thermogravimetry (TGA) and differential scanning calorimetry (DSC). PS-PA was shown to form a stable monolayer at the air-water interface. The positively charged rigid polyacetylene segments are believed to be at the water surface and only partially submerge, while the more flexible hydrophobic polystyrene chains are forced out of the water. Doping with iodine was found to cause a contraction of the monolayer. Uniform and stable multilayers were deposited using both Langmuir-Blodgett and self-assembly deposition techniques without the need for a polyanion. Conductivity measurements of the multilayer assemblies suggested an alternating insulator-semiconductor layer structure of the deposited films.