During the 1980s the share of prescriptions sold by retail pharmacies that was accounted for by generic products roughly doubled. The price response to generic entry of brand-name products has been a source of controversy. In this paper we estimate models of price responses to generic entry in the market for brand-name and generic drugs. We study a sample of 32 drugs that lost patent protection during the early to mid-1980s. Our results provide strong evidence that brand-name prices increase after entry and are accompanied by large price decreases in the price of generic drugs.