OBJECTIVES: Inherited RPE65-related retinal dystrophy is a rare, progressive disease, which until now has had no treatment options. Patients experience decreasing functional vision often from childhood and half of all patients are legally blind by age 18. This study evaluates the cost-effectiveness of voretigene neparvovec, a gene therapy which is the first treatment option ever developed, in a Danish setting. METHODS: A Markov model with annual cycles was developed to describe the disease progression with and without treatment respectively. In the model, patients could go from moderate visual impairment through four additional states of visual impairment, with death as an option from all other states. Costs were based on list prices of drugs and either DRG costs or prices derived from a Danish eye care hospital clinic for cost of treatments. In line with Danish convention, the model focused on the perspective of a healthcare payer and thus, social costs were not included. Discount rates in Denmark follow national guidance in which the rate is 4% in the beginning with a lowering over time. The average rate, weighted by survivors in the model, ended up at 3,5% in the base case. In line with earlier NICE guidance, sensitivity analyses were performed also on lower discount rates given the upfront nature of payments. RESULTS: In the base case, the ICER lands at DKK 834,241 with a QALY gain of 6.27. The results are mostly affected by choice of discount rate and assumptions regarding the duration of treatment effect. It is particularly worth noting that a lower discount rate of 1.5% almost halves the ICER, to DKK 447,034 with a QALY gain of 11.7. The undiscounted QALY gain is 20.1. CONCLUSIONS: With an assumed ICER threshold of DKK 1,000,000 for orphan indications, voretigene neparvovec is cost-effective in a Danish setting.