Differences in the performance of wood and metal baseball bats, measured as a function of batted ball speed, were quantified in a batting cage study. Two wood and five metal baseball bat models were studied with 19 players of various levels of experience ranging from high school to professional. Batted ball speeds from 538 hits were computed from high-speed 3-D ball position data collected with a commercially available system. In general, metal bats had significantly higher batted ball speeds than wood bats. Of the five metal bat models studied, one outperformed all other models and one bat was most similar to wood bats. The average difference in batted ball speed between wood bats and the highest performing metal bat was approximately 9 mph. Maximum batted ball speeds of 101 and 106 mph were measured for wood and metal bats, respectively. Increased skill level significantly increased the maximum batted ball speeds generated independent of bat model. Players of all experience levels were able to generate batted ball speeds in excess of 100 mph. While the results of this study are limited to the specific bats tested, this is the first study to measure and report differences in batted ball speeds among wood and metal bats.