The purpose of this study investigated the effect of government R&D support programs on R&D investment and innovation performance of Korean medium sized enterprises. This study conducted empirical analysis on 284 mid-sized enterprises (including preliminary mid-sized enterprises) with experience in utilizing government R&D support programs in the past three years to achieve this research objective. The analysis results have following findings. First. it was found that government R&D support programs had a positive effect on R&D investment of medium sized enterprises. In the case of mid-sized enterprises, the motivation to apply and use government R&D support programs are to invest in R&D in challenging and high-risk areas rather than securing R&D funds. Second, the government R&D support programs were found to have a positive effect on technology innovation performance of medium sized enterprises. Third, the government R&D support programs were found to have a positive effect on the operating innovation performance of medium sized enterprises. In other words, the government R&D support programs have the effect of securing cost competitiveness through improving existing technologies or improving processes in addition to developing new technologies.