Polycrystalline diamond compact (PDC) tips, which originated with the development of PDC cutters in 1973, have recently been used to fabricate percussion drill bits. In the present study, rotary-percussion drilling tests were carried out to evaluate the performance of two PDC percussion bits, both having a diameter of 65 mm, but containing different types of PDC tips. The drilling medium was hard abrasive granite. For comparison, a WC-Co percussion bit was also tested. The WC-Co percussion bit reached the end of its life at a drilling length of 20.6 m due to large gage loss. In addition, its rate of penetration (ROP) decreased quickly with increasing drilling length due to large height loss at the gage tips. On the other hand, for both PDC percussion bits, a drilling length of 46.8 m was achieved without gage loss and with very small height loss. In addition, the decrease in the ROP with increasing drilling length was much less for the two PDC percussion bits. Thus, the PDC percussion bits exhibit much higher performance than the WC-Co percussion bit. Also emphasized is that we found the fact that the torque on bit detects the height loss on gage tips of all bits. Finally, the drilling costs using the different bits were estimated based on the results of the drilling tests and several reasonable assumptions. It was found that for a drilling length of 80 m, the total drilling costs were almost the same for the PDC percussion bits and the WC-Co percussion bit, even though the bit cost of PDC percussion bits were considerably more expensive.