OBJECTIVES: Retinitis pigmentosa (RP) causes progressive retinal degeneration and blindness. The Argus II retinal prosthesis system can improve visual function in blind patients with advanced RP. We assessed economic implications of the Argus II system for advanced RP in Ontario, Canada. METHODS: We developed a Markov model to determine the cost-effectiveness of the Argus II system compared with standard care in RP patients from the Ontario public payer perspective. The main outcomes of the model were costs, quality-adjusted life-years (QALYs) and the incremental cost-effectiveness ratio (ICER). The model had a 10-year time horizon. Clinical model parameters (effectiveness and safety) of the Argus II system were obtained from the literature. Cost components (Argus II devices, surgery, maintenance of devices and treatment of adverse events were included). We conducted univariate and probabilistic sensitivity analyses to explore the robustness of the model. Costs were expressed in 2015 Canadian Dollars and discounted at 5% annually. RESULTS: In the base-case analysis, compared with standard care, Argus II system resulted in a gain of 1.13 QALYs (3.12 QALYs with Argus II versus 2.08 QALYs with standard care) with an additional cost of $234,606 (CDN) ($361,034 with Argus II versus $126,428 with standard care) over a 10-year time horizon. This translated into an ICER of $207,616 per QALY gained. Univariate sensitivity analyses showed that the model was most sensitive to health-related utility of RP patients, and the cost of implantation and device parameters. Probabilistic sensitivity analyses showed that at the willingness-to-pay amounts of $100,000 and $200,000 per QALY, the probability that Argus II would be cost-effective was 21% and 45%, respectively. CONCLUSIONS: The Argus II system improved the quality of life of RP patients but at a very high incremental cost. Its cost effectiveness would not typically be considered attractive given the incremental cost effectiveness ratio.