Abstract: A bat conditioning device for breaking in or seasoning softball or baseball bats. A preferred conditioning device includes a handle having a first end and a second end, a grip attached to the first end of the handle, and a head attached to the second end of the handle having an impact response that mimics that of a regulation softball. In the preferred form, the head is a regulation softball. The bat conditioning device is of a length that allows softball bats to be broken-in by striking a bat held in one hand of a user, with the conditioning device being held in the other hand.