An extremely low threshold for lasing from a specially formulated system involving self-assembled, aggregated molecules enables the system to function as a mirrorless laser. Superradiant energy states created in coherently coupled aggregated molecules emit photons that stimulate emission from other spatially distributed superradiant states. This study focuses on a cyanine dye (specifically,1,1′-3,3′-tetraethyl-5,5′,6,6′-tetrachlorobenzimidazolocarbocyanineiodide) adsorbed onto silica colloid on which the dye aggregates, forming excitonic states involving coherent domains in which a finite number of molecules act cooperatively in the process of emitting photons. It is found that lasing from such a system is induced at a threshold of ca. 39 pJ/pulse, which corresponds to a factor of3×10+4times smaller than the lowest lasing threshold reported in the literature. ©1997 American Institute of Physics.