We made a comparative cohort study in patients suffering from tibial pseudoarthrosis, all of whom were treated by intramedullary nailing. We divided patients into two groups: one treated by intramedullary nailing only (control group) and the other by intramedullary nailing combined with pulsed electromagnetic fields (PEMFs). The study included 57 cases of tibial pseudoarthrosis in 57 patients from February 1987 to February 2002. Pseudoarthrosis was treated surgically in all cases (Grosse-Kempf dynamic intramedullary nailing). This was combined with PEMFs in 22 cases. The average age was 38.3 years (range 14-89 years) and the average duration of follow-up was 27.2 months (range 12-48 months). Forty-nine fractures (86%) healed and eight (14%) did not. Of the group treated with PEMFs, 20 (91%) healed and two (9%) did not; from the group that did not receive PEMF (35), 29 (83%) healed compared to six (17%) that did not. The relationship between union and use of PEMFs, and between time to union and use of PEMFs was clinically relevant. PEMFs are useful when treating tibial pseudoarthrosis. Its noninvasive nature means that there are more complication-free unions.