BACKGROUND The aim of this study was to evaluate the long-term outcome of deep sclerectomy (DS) with a follow-up of up to 8 years. METHODS All patients who underwent a deep sclerectomy between February 2004 and October 2005 and who attended a follow-up visit between August 2009 and October 2011 were included in this study. RESULTS This study evaluated 74 eyes of 65 patients with a mean postoperative follow-up of 76.28 ± 10.6 (53.65-92.02) months. Preoperative IOP was 18.37 ± 6.36 mmHg, postoperative IOP at the last follow-up was 12.85 ± 3.5 mmHg, corresponding a 30 % reduction. The number of IOP-lowering eye drops was reduced from 2.36 ± 1.24 to 1.66 ± 1.21 after more than 6 years (p < 0.05). The visual fields showed a mean deviation of - 9.16 ± 8.48 dB initially and - 9.43 ± 8.07 dB at the last follow-up (p > 0.05). Complete success (IOP ≤ 15 mmHg without eye drops or additional surgery) was achieved in 5 % of patients. Qualified success (IOP ≤ 15 mmHg with eye drops or additional surgery) was achieved in 81 %. 53 % (n = 39) underwent cyclophotocoagulation and 20 % (n = 15) needed revision surgery during the follow-up period. CONCLUSIONS DS is an effective long-term IOP-lowering procedure leading to visual field stabilisation.