In this study, impact resistance of grinding wheels made from organic composites and strengthened with glass-fiber composites is investigated. A pendulum system was developed to apply the impact load. Four different parameters were included: (1) wheel service condition (static versus dynamic); (2) wheel impact position (side versus face impact); (3) impact location (edge versus inner area); and (4) size of the steel impact indentor. The test results show that the developed impact testing method was reliable and effective. The wheels under the dynamic spinning condition are more vulnerable to impact than under the static condition, and are more prone to damage when being impacted on the vertical side than on the flat circular grinding surface. In addition, more severe damages are observed when the inner area of the grinding surface is under impact rather than the outer area. The steel indentor with the smaller dimension causes more damage than those of larger size.