Objectives: To define the safety profile of trainee trabeculectomy surgery in the United Kingdom. Surgical exposure for trainees in England is limited due to service requirements, the European working time directive constraints and increasing sub-specialisation of glaucoma surgery. Limited knowledge exists on the outcomes of supervised glaucoma surgery. The aim is to determine the safety of supervised trabeculectomy surgery performed by trainee ophthalmologists. Methods: Retrospective case note review of all patients that had trabeculectomy surgery with MMC by consultant and trainee surgeons across multiple UK centres. All eyes have 2-year follow up. Success was determined using WGA guidelines. Two-tailed p values were obtained using Fisher's exact test to ascertain statistical significance between groups. Main outcome measures: intraocular pressure, visual acuity, success and failure rates. Results: 324 eyes were reviewed. 211 (66.4%) cases were performed by glaucoma consultants, 107(33.6%) by trainee ophthalmologists. The majority of eyes in each group were undergoing surgery for POAG. Post-operative IOP control showed no significant difference between consultant and trainee groups at year 1 and year 2. Success rates showed no significant difference between consultant and trainee cases. Failure rates at year 1 showed a significant difference between the two groups. No significant difference was seen at year 2. The trainee group had significantly more complications, when compared with the consultant group. Snellen visual acuity loss was not statistically significant between the two groups at the 2 year time point. Conclusions: The outcomes of supervised trainee trabeculectomy compare favourably with consultant cases after 2 year follow up. Trainee cases had higher complication rates than consultant cases. Bleb leaks are a common complication of trainee cases, where closer supervision may be required. There is potential for surgical simulation to help increase the success of such cases. These findings may encourage trainee participation in glaucoma surgery.