It is increasingly becoming important for firms to innovate, because technological developments have
accelerated and customer needs have diversified. A firm needs to perform innovation to achieve high
performance and sustainable competitive advantage. However, even though the type of innovations is largely
divided into product innovation, process innovation, organizational innovation, and marketing innovation, it
is still lacking to consider causal relationships. Therefore, this study investigates the relationships among
four innovations for firms to improve innovation performance through Korean Innovation Survey (KIS) data
of Science and Technology Policy Institute (STEPI). Especially, firms will have to perform organizational
innovation before other innovations as it changes their internal routines. The results show that organizational
innovation is positively associated with innovation activities (process innovation and marketing innovation),
except for product innovation. This study confirms causal relationships among four innovations, and we
suggest the importance of organizational innovation. Firms have to consider the role of organizational
innovation when they perform innovation activities in the future.