The present invention provides an optical recording medium that includes a recording layer composed mainly of an organic compound and can utilize blue-violet semiconductor laser light (390 to 420 nm in wavelength) as recording/reproducing laser light. The present invention also provides an optical recording/reproducing method using the optical recording medium. The optical recording medium 1 comprises at least a supporting substrate 2; a recording layer 3 on the supporting substrate 2, the recording layer 3 containing an organic compound as a major component; and a light-transmitting layer 5 on the recording layer 3, the light-transmitting layer 5 being capable of transmitting laser light with a wavelength of 390 to 420 nm for recording and reproducing information. The organic compound in the recording layer 3 includes a monomethine cyanine dye that has the minimum value n.sub.min of its refractive index n (real part of the complex refractive index) within the range of 370 to 425 nm and has a refractive index n of 1.2 or lower with respect to the wavelength of the recording/reproducing laser light. The organic compound, when absorbing the laser light, melts or degrades to bring about a change in the refractive index, thereby effecting recording of the information.