Initially developed to reduce intramedullary pressures during long bone intramedullary nail placement, the reamer–irrigator–aspirator (RIA) can be used to harvest large volume autologous bone graft from the intramedullary canal of a long bone. This case-based surgical technique video demonstrates the appropriate techniques that should be applied while using the RIA to obtain autologous bone graft from the femur. A large volume of bone graft, generally between 30 and 90 cm3, can be obtained using a single RIA procedure. The bone graft harvested from the intramedullary canal is excellent regarding its biochemical properties, with several studies reporting higher levels of growth factors and stem cells when compared with iliac crest bone graft. Surgical technique is key to maximize bone graft harvest, as well as to avoid complications including iatrogenic fracture, intraarticular penetration, and fragmentation of either the reamer head from the drive shaft or the guide wire. Pearls and pitfalls regarding sizing of the reamer head, determination of starting point, guide wire placement, reamer advancement, and diligent use of fluoroscopic imaging are highlighted during this video. Finally, outcomes regarding healing of long bone defects when using RIA-derived autologous bone graft and reduction in postoperative pain at the graft donor site are briefly reviewed.