The most common fracture of the proximal fifth metatarsal is the tuberosity avulsion fracture. Most of the time, the fracture is relatively undisplaced and it can be treated conservatively with a hard-soled shoe or walking cast. For painful intra-articular nonunion, internal fixation with or without bone graft is the treatment of choice. We describe an endoscopic approach to treat nonunions of the tuberosity avulsion fracture. Under endoscopic guidance, the nonunion site can be debrided thoroughly and bone grafted without the need of extensive soft tissue dissection. Moreover, the condition of the fifth metatarsal cuboid articulation can be assessed and intra-articular pathology can be dealed with arthroscopically. Finally, the desired position of the screw can be guided by the arthroscopic aiming device.