[en] This study explores the causes of the South Korean government's failure to successfully deploy its renewable energy policy. Despite the South Korean government’s ongoing efforts since 2002 to promote the deployment of renewable energy, the established deployment target has not been met and the share of renewable energy supply in total primary energy supply is poor compared to peer countries with a similar level of economic development. Therefore, we attempt to find the causes of this policy failure using qualitative evaluation methods. Through the analyses, conducted using focused interviews and secondary data, we found that the domination of the fossil fuel and nuclear power industry's interests, inconsistent policy shifts, policy design that lacks sufficient support schemes, poorly coordinated government activities, and unsystemic and untimely monitoring and feedback have led to the failure of renewable energy deployment policies in South Korea. To overcome these problems, we suggest that the South Korean government should set more ambitious policy goals, establish a new independent organization that focuses on energy policy issues, use a varied policy mix, and secure political support from diverse policy actors. - Highlights: • We identify factors for successful renewable energy deployment policies. • We construct an evaluation framework based on the established literature. • We analyze data collected from focused interviews and secondary materials. • There exists an overall weakness throughout all renewable energy policy phases. • We recommend some policy prescriptions based on the evaluation results.