OBJECTIVES: To assess the cost-effectiveness of rotigotine transdermal patch relative to placebo and oral dopamine agonists (ropinirole and pramipexole) in the treatment of moderate-to-severe idiopathic restless legs syndrome (RLS) from the perspective of National Health Service (NHS) Scotland. METHODS: A cost-utility analysis was conducted using a decision tree in order to measure the cost per quality-adjusted life-year (QALY) gained resulting from the treatment of moderate-to-severe idiopathic RLS in 2008. Clinical, safety and quality of life data were extracted from the literature. The decision analytic model was run for a 1-year time horizon in the base-case analysis. The model included direct medical costs, augmentation rate and the most common adverse events. Sensitivity analyses assessed the effect of varying the time horizon to 9 months, 2 and 5 years. An annual discount rate of 3.5% was applied to costs and benefits for analysis beyond 1 year. RESULTS: Over a 1-year period, treating patients with rotigotine would result in a total cost of £1658 per patient as compared with £606, £1152 and £1055 for placebo, ropinirole and pramipexole respectively. Treatment with rotigotine resulted in 0.842 QALYs gained compared with 0.691 for placebo, 0.753 for ropinirole and 0.780 for pramipexole. The cost per QALY gained for rotigotine was £6990 versus placebo, £5725 versus ropinirole and £9729 versus pramipexole. Probabilistic sensitivity analysis has shown that the probability of rotigotine being cost-effective compared with placebo, ropinirole and pramipexole is greater than 0.90 at a willingness to pay threshold of £13,000. At a threshold of £20,000, the probability of rotigotine being more cost-effective is close to 1 versus placebo and ropinirole and 0.93 versus pramipexole. CONCLUSIONS: Rotigotine transdermal patch was shown to be a cost-effective treatment in patients with moderate-to-severe restless legs syndrome from the payer’s perspective (NHS Scotland).