Therapeutic doses of indomethacin, aspirin, and ibuprofen were administered to New Zealand White rabbits after implantation of a porous-coated chrome-cobalt implant. Quantitative histomorphometric analysis was used to calculate the amount of bone occupying the pores. There was a statistically significant decrease in bone ingrowth in animals treated with indomethacin, ibuprofen, and high-dose aspirin when compared to a control group. There was a dose-response effect for the indomethacin and aspirin groups, with higher doses having a greater inhibitory effect. Indomethacin, ibuprofen, and high-dose aspirin may be contraindicated during the immediate postoperative period in patients having cementless arthroplasty.