In the repair of orbital blowout fractures through eyelid or conjunctival incision, it is difficult to see the posterior edge of the fracture and the condition of the herniated tissue before reduction of the orbital contents. Prolapsed orbital tissue or infraorbital nerve and vessels may therefore be damaged in the reduction. The recently advocated combination of traditional transconjunctival approach and endoscopic transantral approach allows reduction and reconstruction under clear endoscopic vision without a facial skin incision. We modified this technique to make it less invasive and applied it to the repair of orbital blowout fractures involving the orbital floor. The use of a 70-degree straight endoscope through an enlarged ostium as for functional sinus surgery allowed clear sight of the roof of the antrum. During the repair of the orbital floor through a transconjunctival approach, reduction and reconstruction was assisted from the antrum. Twelve cases of fresh blowout fractures were treated with this approach. There were seven male and five female patients. Mean age was 23.5 years. Causes of injuries were fights, motor vehicle or bicycle accidents, and sports. Patients with concomitant fractures involving the orbital rim were excluded. Persistent diplopia was present in eight cases and enophthalmos of more than 2 mm was detected in five cases preoperatively. The average intervals from injury to surgery was 22.8 days.Exploration, reduction and reconstruction of the orbital floor fractures were precisely performed with this procedure. Large orbital floor defects were reconstructed with silicone sheets, thin iliac bone grafts or nasal septal cartilage. In all eight cases that showed diplopia, ocular movement recovered and symptomatic diplopia disappeared after surgery. Enophthalmos of more than 2 mm was also improved in all five cases. One early case showed temporary entropion. Transient numbness of the cheek appeared in five cases and temporary maxillary sinusitis recovered in one case. Postoperative infection was not observed.This method provides visualisation of posterior edge of the fracture and the condition of herniated orbital contents before initiation of reduction. Dual manipulation by two surgeons is also possible in reduction and reconstruction of the orbital floor.