The presence of ethanol (5 % v/v), in nutrient medium, ehanced DNA synthesis per E. coli cell nearly 2.8.-fold compared to that in control cells. At this concentration, the derepressed synthesis of beta-galactosidase per bacterium also increased about 3-fold. We, therefore, propose that the ethanol-mediated gene-amplification proportionately elevated the induced synthesis of beta-galactosidase.