Objective: To assess the outcome of supplemental transscleral diode laser cyclophotocoagulation after aqueous tube shunt placement to obtain effective intraocular pressure (IOP) control. Design: Retrospective noncomparative case series. Participants: Twenty-one eyes in 21 subjects with uncontrolled IOP despite the presence of an aqueous tube shunt and maximally tolerated glaucoma medications. Intervention: Supplemental transscleral diode laser cyclophotocoagulation was performed. Main Outcome Measures: Reduction of intraocular pressure and reduction of glaucoma medications. Results: Twelve adults and nine children underwent supplemental transscleral diode cyclophotocoagulation and were followed postoperatively for a mean of 26.9 ± 13.4 (standard deviation [SD]) months (range, 7-58 months). Average IOP was significantly reduced from a preoperative level of 35.7 ± 14.7 (SD) mmHg to a postoperative level of 13.6 ± 7.1 (SD) mmHg (P < 0.001) with the mean number of medications significantly reduced to 1.5 ± 1.3 (SD) (P < 0.001). Seven subjects (33%) had additional laser treatment to achieve IOP control. Six subjects who were therapy failures included three who developed no light perception in the setting of proliferative diabetic retinopathy, one subject with chronic angle-closure glaucoma who gradually developed no light perception after refusing further treatment or medication, and two subjects who developed retinal detachments. One child who was a qualified success underwent enucleation and debulking of an enlarging neurofibroma that caused significant proptosis and disfigurement. Conclusions: In cases of glaucoma that are uncontrolled despite a glaucoma aqueous tube shunt and multiple medications, adjunctive transscleral diode cyclophotocoagulation treatment(s) is a viable option to lower IOP.