As S. Korea is becoming an “aged society”, workers in the country would be exposed to higher risk of workplace injuries due to their reducing work abilities as they are getting old. To identify the relationship between the work ability and the incident rate of workplace injuries, the work ability index (WAI) scores were surveyed from 409 workers occupied in different manufacturing industries reside on north GyoengBuk area. The workplace injury statistics in the year of 2010 for the corresponding industries were analyzed and summarized with the WAI scores by age groups, years of service, and sizes of business. The results showed the WAI scores of the workers occupied in the higher risk of workplace injury was lower than that of the workers of the lower risk. It means the lower the WAI score, the higher the chance of being injured during the task. It is concluded that appropriate correlation exists between the WAI scores of workers and the incident rate of workplace injury. It is recommended to administrate individual work abilities of aged workers in order to keep low rate of workplace injuries in upcoming aged and highly aged society.