When infielders field a ground ball, decreasing the interval from catching to releasing the ball (release time) increases the probability of outing a batter or runner. The present study examines the relationship between lower extremity kinematics and release time. Right-handed fourteen infielders caught a ground ball that was rolled towards them from a distance of 5 m and then they threw the ball as quickly as possible towards a net located 20 m in front. The interval between the catch to the left-foot lift-off (foot off phase), and the stride-foot contacting the ground after the step motion (stride phase) significantly correlated with release time. We assessed relationships between these phases and lower extremity movement. The angular variation of the joints of the right lower extremity from the catch to the right foot lift off significantly correlated with the foot off phase. Forward mid-hip and left foot variation significantly correlated with the stride phase. Velocity data did not significantly correlate with these phases, indicating that the size, rather than the speed of the fielding motion has a greater effect on release time.