A diverse set of observations from Archaean fossil-bearing rocks, modern submarine hydrothermal systems, experimental and theoretical work on the abiotic synthesis of organic molecules and primitive organized structures, and on water-rock interactions suggests that submarine hot springs were the site for the synthesis of organic compounds leading to the first living organisms on earth. These systems are characterized by high fluxes of thermal energy, highly reducing conditions, abundant and appropriate catalytic surface areas (Fe-Mg clay minerals), significant concentrations of CH sub(4), NH sub(3), H sub(2), metals, etc., and a continuous convective flow which removes products from the site of reaction upward through a mixing gradient of temperature and composition. It is hypothesized that the sequence of reactions CH sub(4), NH sub(3), H sub(2) arrow right amino acids arrow right proteins arrow right complex polymers arrow right metabolizing organized structures arrow right living organisms could occur within and/or adjacent to these systems. Microorganisms found in carefully preserved samples of sulfide chimneys from the East Pacific Rise may be counterparts of Archaean fossil organisms.