Innovation can enhance the usefulness of products and services, but technological innovation may be hindered by many potential barriers. One important potential barrier is patent infringement litigation. In this study, we review the relationship between US patent features and US patent litigations, identify potential patent risk factors, and quantitatively evaluate patent infringement litigation risk. We find that certain factors do have significant impacts. By identifying these risk factors, we may manage product development strategies and patent application strategies to avoid being litigated by competitors. The difference between patents filed before and after the Leahy–Smith America Invents Act is also reported.