Various materials are used in orbital blowout fracture repair. We describe a series of patients with orbital blowout fractures that were repaired using porous polyethylene (Medpor) sheets.A non-comparative interventional case series is described of 30 blowout fractures of 30 patients aged 7-60 years (median 29 years) who underwent orbital blowout fracture repair with Medpor sheets. The mean follow-up was 19.1 months (minimum 5 months). The indication for surgery in 6 cases was non-resolving diplopia. The remaining 24 cases had surgery for enophthalmos. Ten cases underwent primary or secondary hydroxyapatite orbital implantation at the same time as orbital floor blowout fracture repair. Data were collected on postoperative motility and diplopia, enophthalmos, cosmesis, complications and re-operations.In no case was diplopia worsened by blowout fracture repair. Where surgery was performed for the correction of enophthalmos, late surgery did not compromise the surgical results. There were no intraoperative complications. The one major complication was a case of recurrent implant infections leading to implant removal. There were 3 minor postoperative complications: 2 cases of postoperative infraorbital anaesthesia and one case of a palpable titanium screw. Re-operations were performed for pre-existent diplopia, lid laxity, socket abnormalities and mid-facial deformities. None of these arose from the blowout fracture repair.The study suggests that in orbital blowout fracture repair Medpor implants are safe and effective with few complications. Late surgery for enophthalmos is technically more difficult but is not associated with poorer functional or cosmetic results.