We performed a clinical study of the effect of electrical current on the congenital pseudarthrosis of the tibia from May, 1980 to January, 1984. Eight congenital pseudarthrosis were treated with direct current stimulation, six of which had received previous treatment at least more than one time in any manner and two had none. Four were failures in previous treatment with vascularized fibular graft due to the non-uoion at the proximal or distal sites of grafted bones. Six of eight congenital pseudarthrosis were treated with invasive type electrical stimulators, and the remaining two were treated with semi-invasive type. The average follow-up period was 26 months (range from 8 to 39 months). As a result satisfactory union has occured in seven out of eight cases. The mean time for union was 27 weeks (range from 15 weeks to 48 weeks). No serious complication was observed, but in our experience, the semi-invasive type, comparing to invasive type, was handicaped with minor complications such as pin tract infection and skin sloughing due to the irritation by anode pad, and needed frequent recharging to maintain adequate voltage. With above result, we think that the electrical stimulation has revealed to be one of the reliable methods in the treatment of surgery-resistant congenital pseudarthrosis.