OBJECTIVES: Large amounts of health care cost are spent on drugs in Korea, 29.6% of total health care expenditure in 2009, and these amounts are continuously increasing. To control spending on prescription drugs we had tried to adopt the reference pricing system in 2001, but it failed due to patients’ negative perception and shortage of infrastructure. Recently, it is estimated that the technical circumstances are prepared. Yet the public perception has not been checked whether it has been changed or not. The aim of this study was to ascertain the patients’ willingness to exchange the prescribed drug for the cheaper one in order to predict the acceptability of the reference price system. METHODS: Nation-wide telephone interview survey was conducted for 1000 consumers from October 19 to 26, 2011. RESULTS: Patients were asked whether they would exchange the drug prescribed by their doctor for the cheaper drug of which therapeutic effectiveness is equivalent. Of 1000 respondents, 647(64.7%) answered “Yes (I will exchange)”. And the reasons of the 353 consumers who responded “No (I will not exchange)” are; their trust in doctor’s judgment (56.1%, n=198), little confidence in the equivalence between the medications (35.1%, n=124), and there is no great difference among the cost of medicines in general (8.8%, n=31). CONCLUSIONS: Patients’ attitude toward lower price drug has been changed for last 10 years in Korea. They would likely to choose cheaper drugs if information of exchangeable drug options and prices is given at the time of prescribing or dispensing. It means that reference price system would be acceptable by patients and contribute to reduce the pharmaceutical expenditure in Korea. In addition, providing physicians with incentives to encourage prescribing low price medicines and restoring consumer confidence in equivalence of therapeutic effect are required to improve the effectiveness of the system.