Inasmuch as raising the efficiency of pharmaceutical expenditures is an important policy goal toward keeping the National Health Insurance financially sustainable, off-patent drugs are regarded as a market with significant potential. Pharmaceutical expenditures have been growing more rapidly in Korea than in any other OECD country. It is crucial thus to add efficiency to Korea’s pharmaceutical expenditures. Drawing on a survey of consumer perception of prescription drug prices, this study attempts to add to the understanding of consumer choice of drugs and to suggest ways to increast the efficiency of pharmaceutical spending.