OBJECTIVE: Evaluate whether supplementary fibular fixation helped maintain axial alignment in distal metaphyseal tibia-fibula fractures treated by locked intramedullary nailing. DESIGN: Retrospective chart and radiographic review. SETTING: Three, level 1, trauma centers. PATIENTS: Distal metaphyseal tibia-fibula fractures were separated into 2 groups based on the presence of adjunctive fibular plating. Group 1 consisted of fractures treated with small fragment plate fixation of the fibula and intramedullary (IM) nailing of the tibia, whereas group 2 consisted of fractures treated with IM nailing of the tibia without fibular fixation. OUTCOME MEASURES: Malalignment of the tibial shaft was defined as 1) >5 degrees of varus/valgus angulation, or 2) >10 degrees anterior/posterior angulation. Measures of angulation were obtained from radiographs taken immediately after the surgery, a second time 3 months later, and at 6-month follow-up. Leg length and rotational deformity were not examined. RESULTS: Seventy-two fractures were studied. In 25 cases, the associated fibula fracture was stabilized, and in 47 cases the associated fibula fracture was not stabilized. Cases were more likely to have the associated fibula fracture stabilized where the tibia fracture was very distal. In multivariate adjusted analysis, plating of the fibula fracture was significantly associated with maintenance of reduction 12 weeks or later after surgery (odds ratio = 0.03; P = 0.036). The use of 2 medial-lateral distal locking bolts also was protective against loss of reduction; however, this association was not statistically significant (odds ratio = 0.29; P = 0.275). CONCLUSIONS: In this study, the proportion of fractures that lost alignment was smaller among those receiving stabilization of the fibula in conjunction with IM nailing compared with those receiving IM nailing alone. Adjunctive fibular stabilization was associated significantly with the ability to maintain fracture reduction beyond 12 weeks. At the present time, the authors recommend fibular plating whenever IM nailing is contemplated in the unstable distal tibia-fibular fracture.