PURPOSE: Blow-out fractures can be reduced using various methods. The orbital reconstruction technique using a balloon under endoscopic control has advantages over other methods. However, this method has some problems too, such as postoperative follow-up, management of the balloon catheter, and reduction of the posterior orbital floor. Thus, we developed a simple, effective method for orbital floor reduction that involves molding and shaping the antral balloon catheter. METHODS: A 0, 30, or 70degrees, 4-mm endoscope was placed though a two-point, 5-mm maxillary antrostomy. The balloon catheter is placed directly at the orbital apex to reconstruct the anterior shelf(spherical shape), while it is turned in a U-shape towards the anterior maxilla for the posterior shelf(elliptical shape). Orbital floor defects, compound or comminuted fractures are reconstructed with alloplastic materials through an open lid incision under the endoscopic control. RESULTS: This technique was applied to ten patients with orbital floor fractures: five anterior shelf and five posterior shelf fracture, respectively. Four of the patients had zygomatico-orbital fractures, while the rest had isolated orbital floor fractures. Two patients were given porous polyethylene implants(Synpor(R)) and three underwent reconstruction with a resorbable mesh plate. No complication associated with this technique was identified. CONCLUSION: The freestyle placement and selection of a urinary balloon catheter under endoscopic control and the preoperative estimation of the volume enhanced the stabilization of the orbital contour. This method improves the adaptation of the orbital floor without the risk of injuring the surrounding orbital contents, dissecting blindly, or using sharp traction. One drawback of this method is the patient's discomfort from the catheter during treatment.