OBJECTIVE We evaluated functional results with the Ilizarov circular external fixator in the treatment of open tibial fractures. METHODS Thirty-three patients (26 males, 7 females; mean age 38 years; range 16 to 69 years) with open tibial fractures were included. According to the AO/OTA classification, there were seven type A, 16 type B, 10 type C fractures; according to the Gustilo-Anderson classification, eight, 12, and 13 fractures were grade I, II, and III, respectively. The mean time to surgery was 5.7 days (range 3 to 12 days). Compression-distraction was applied in five patients to speed up union. Functional outcomes were assessed according to the Karlstrom-Olerud scoring system. The mean follow-up was 28 months (range 19 to 34 months). RESULTS Time to union did not differ significantly between grade I and II fractures (p>0.05). However, there were significant differences between grade I and III (p=0.0001) and grade II and III (p=0.001) fractures with respect to union times. According to the Karlstrom-Olerud scores, functional outcome was good in 14 (42.4%), satisfactory in 11 (33.3%), and fair in eight (24.2%) patients. The most common complication was pin tract infections (28.4%). Seven K-wires were replaced. Two patients (6.1%) who developed osteomyelitis underwent sequestrectomy following removal of two K-wires. Peroneal nerve injury occurred in two patients associated with K-wires. Ankle and knee movements were adversely affected due to the external fixator in seven and four patients, respectively. CONCLUSIONS Although the use of the circular external fixator is associated with a relatively high risk of pin tract infections, functional results may justify its use in the treatment of open tibial fractures, with an added advantage of early mobilization.