An organic vertical cavity surface emitting laser has been fabricated, using a Forster energy transfer system of organic pyridium salt dye ASPI and Alq3 doped in PMMA film as the gain medium, which was sandwiched between a high-reflectance distributed Bragg reflector and a silver reflector. The stimulated emission properties were investigated by nanosecond-pulsed laser pumping. The lasing phenomenon was observed with a full width at half maximum of 243 nm at the lasing wavelength of 600 nm, and the threshold energy for lasing was estimated to be about 8?J per pulse.