Picosecond optical bistable behaviors in an optical quasi-waveguide and a planar waveguide made with metallophthalocyanine-doped polymer films were demonstrated. Input-output curves with hysteresis characteristics were measured at 532 nm. In the quasi-waveguide through the observation on the bistabilities of the reflected light at various offset angles, the responsibility of high-order modes for the bistable behaviors was investigated by using the mode spectra. The non-linearity giving rise to optical bistability was predominantly electronic in origin.