Lateral tibial plateau fractures that are located posterolaterally are difficult to reduce through an anterolateral surgical approach because of the lack of direct visualisation of the fracture. This study compared the results of unicondylar posterolateral tibial plateau fractures in two patient cohorts: one treated through a posterolateral direct approach and the other through an anterolateral indirect approach. All nine patients admitted to our hospital, a tertiary care, urban, public hospital in Australia, from 2007 to 2010 with unicondylar posterolateral tibial plateau fractures were treated through a direct posterolateral transfibular approach and prospectively studied. All eight patients admitted from 2004 to 2007 with unicondylar posterolateral tibial plateau fractures were treated through an indirect anterolateral approach and retrospectively reviewed. Fracture reduction and maintenance of reduction were assessed radiographically over 2 years. Knee function was assessed clinically and using the Lysholm score. Fractures managed through a direct posterolateral transfibular approach were reduced with no measurable articular step on standard radiography and had no loss of reduction over time. By contrast, fractures treated through an indirect anterolateral approach had a median postoperative articular step of 5.5mm (interquartile range=4.5). These displacements worsened over time in six of the eight patients. At 2 years, patients treated through a direct approach had significantly better Lysholm scores than those treated through an indirect approach. This study suggests that a direct posterolateral transfibular approach to unicondylar posterolateral tibial plateau fractures results in improved reduction, stabilisation and functional outcomes at early follow-up compared to an indirect anterolateral approach. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.