The phenomenon of surface-enhanced Raman scattering (SERS) can provide a powerful means for in situ , sensitive, and highly specific observation of adsorbates on metal surfaces. A historical background, the fundamental characteristics, and a number of applications of SERS published to date are reviewed. Emphasis is placed on our recent results concerning the nature of “active sites” in SERS. The applicability of SERS to problems in silver halide photographic science is brieflydiscussed.