OBJECTIVE Ciliary photocoagulation was used to reduce pressure in eyes with refractory glaucoma or to suppress pain in blind painful eyes. The efficiency of transscleral cyclophotocoagulation (TSCPC) with a clinical diode laser system (Iris Medical Instrument, Oculight SLX) was evaluated. METHODS This diode laser system (wavelengh: 810 nm) provides light energy to the eye through a specially designed quartz glass fiberoptic probe allowing precise location centered 1.2 mm behind the limbus, i.e. in front of the ciliary body. Thirty eight eyes in 38 patients with refractory glaucoma underwent TSCPC with the diode laser. RESULTS Three months after surgery, intra-ocular pressure was controlled at 20 mmHg or below in 70% of the patients. Patients who most failed with the TSCPC had higher initial IOP (neovascular and congenital glaucoma). Seventy five percent of the painful glaucoma were painless after the laser treatment. Only a few cases (10%) of transient secondary hypertony were observed. The inflammatory response (21%) was mild and transient. No case of scleral perforation, no case of posterior uveitis, cararact or hypotony were observed. CONCLUSIONS The transscleral ciliary photocoagulation laser diode system is efficient to reduce intraocular pressure in refractory glaucoma. Complications are mild compared with other methods of cyclophotocoagulation. A long-term study is necessary to evaluate the results on IOP and the incidence of hypotony.