Poly(2-methoxy-5-trimethylsilyl-1,4-phenylenevinylene) (PMTSPV) was prepared as thin film via the water-soluble precursor route, and its electrical and optical properties were studied. The conductivity values of drawn (L/L(0) = 7) and undrawn FeCl3-doped PMTSPV films were 0.1 and 0.5 S . cm(-1), respectively. The electroluminescence device was fabricated with PMTSPV as an emitting layer, and ITO and aluminium as hole-injection and electron-injecting electrodes, respectively. The threshold voltage of the device was about 4 V, and the emission maximum was at about 560 nm, with quantum efficiency of 2 x 10(-4)% (emitted photons per electron), which corresponds to yellow light emission. The chi((3)) for the PMTSPV film was investigated by using the third-harmonic generation method at 1907 nm fundamental wavelength, and found to be 1.0 x 10-(11) esu.