To examine the effects of electrical stimulation on bony fixation of intramedullary metal stem in rabbits, the rabbits' tibiae were osteotomized, inserted with either of two kinds of metal rods, titanium alloy or cobalt-chrome alloy, and stimulated with a capacitively coupled electrical signal (10V peak to peak, 60 kiloherz, symmetrical quadriangular wave) which was applied non-invasively over the skin of the rod insertion site. Each tibia of the electrically stimulated group was evaluated with roentgenographic and biomechanical tests after 3 or 6 weeks, and was compared with that of the nonstimulated control group. Electrically stimulated group showed significantly enhanced bony fixation of intramedullary metal stem compared with nonstimulated group by enhancing the bone formation at the rod insertion site, but there was no statistically significant difference between the titanium alloy and cobaltchrome alloy rod insertion groups.