Medial or lateral-based wedge osteotomy around the knee is a procedure that is now gaining more popularity with the current trends in knee preservation surgeries. It is, however, a technically demanding procedure and can result in significant complications. They include fracture, neurovascular injury, delayed and nonunion, thromboembolic disease, infection and under correction or recurrence of deformity. High tibial osteotomy (HTO) and distal femoral osteotomy (DFO) have substantial complication rates in the short and mid-term, with a higher rate of overall complications observed after DFO as compared to the HTO cohort. The knowledge of the complications of HTO and DFO is critical for both the surgeons and the patients to understand, and in this chapter, we shall discuss these in detail.