Purpose LHON is a mitochondrial disease resulting in progressive, severe central vision loss, which is caused by 1 of 3 mitochondrial DNA mutations in >95% of patients. Idebenone, at a dose of 900 mg/day, is effective and safe in patients with LHON. Here, we report long‐term treatment outcomes in real world clinical practice. Methods The Expanded Access Program (EAP) assessed idebenone's therapeutic potential in patients with onset of symptoms within 1 year prior to enrollment. Efficacy was assessed as clinically relevant recovery (CRR) or clinically relevant stabilization (CRS). CRR is defined as improvement from off‐chart to reading 5 letters on the ETDRS chart, or as an improvement of 10 letters. CRS is defined as maintenance of VA <1.0 logMAR (20/200). Results 85 patients carried one of the 3 most common mutations and had at least 1 post‐baseline (BL) visual acuity (VA) assessment. At BL, median age was 23.6 years and median treatment duration at last observation was 17.3 months. A subset of 25 patients presented with VA <1.0 logMAR, from which 52% experienced CRS. CRR from nadir was observed in 51% of patients. The number of eyes which remained on chart increased from 51% at nadir to 67% at last observation, and those <1.0 logMAR increased from 7% to 27%. At BL, 9% of patients were <1.0 logMAR in both eyes, which increased to 23% following treatment. The proportion of patients with CRR increased with treatment duration, with approximately 50% observed up to 6 months, but extending up to 18 months. CRR and CRS were observed, to different degrees, regardless of mutation. Conclusions Idebenone has a good safety profile for the long‐term treatment of LHON, and when initiated early, can stabilize good residual vision and prevent severe vision loss and blindness in a large proportion of patients. Maximal benefit may be achieved by prolonged treatment.