This study assessed the effect of simultaneous implementations of different intellectual property (IP) protection mechanisms on a firm's product innovation performance (PIP). The study categorized seven widely‐used IP protection mechanisms (IPPMs) into two groups: formal and informal. Complementarity was then tested within and between the formal and informal groups of IPPMs. The result showed that there existed complementarity when multiple IPPMs were implemented from the same groups. Throughout an additional analysis on the moderating effect of the industrial complexity in technology, it was found that the ‘between groups' combination effect was also existed but varied from even negative to positive concluding that industrial complexity of technology moderates the effects of combinations of IPPMs on a firm's PIP. These results imply that the use of multiple IPPMs is effective but the effect varies by the technological complexity of industry.