The subvastus or Southern approach to the knee had been described as early as 1929 but is not found in standard modern orthopedic textbooks. This approach for primary total knee arthroplasty (TKA) preserves the integrity of the extensor mechanism and maintains the vascular supply to the patella. To appreciate the potential benefits of this approach, a complete understanding of the surgical anatomy is essential. The benefits of the subvastus approach make it a valuable technique for primary TKA.