The purpose of this study was to clarify the effects of steroid administration on the osseointegration of pure titanium implants. Twelve female New Zealand white rabbits, 8 weeks of age, were divided into two groups: a prednisolone-treated group (Group P) and a control group (Group C). In each rabbit, two implants were placed into the mandible and two into the tibial metaphyses with bone tapping. The six steroid-treated rabbits received three courses of 4 days of prednisolone injections (10 mg/kg per day) before implant placement, 1 month and 2 months after implant placement. The six control rabbits received no administration of prednisolone. Three months after implant placement, all rabbits were sacrificed. Bone density of the femur and removal torque of the implants placed in the tibia were significantly lower in Group P than in Group C. In addition, there were significant correlations between the bone density of the femur and the removal torque of the implants placed in the tibia. There was no significant difference in removal torque of the implants placed in the mandible between Group P and Group C, and there was no significant correlation between the bone density of the femur and the removal torque of the implants placed in the mandible. These results suggest that steroid administration could have less effect on the osseointegration of titanium implants in the mandible than in the skeletal bone. Keywords: microdensitometry, rabbit, removal torque, steroid-induced osteoporosis, titanium implant