Aims: to investigate the cost-effectiveness of a pharmacogenetic dosing algorithm versus a clinical dosing algorithm for coumarin anticoagulants in The Netherlands. Materials & methods: A decision-analytic Markov model was used to analyze the cost-effectiveness of pharmacogenetic dosing of phenprocoumon and acenocoumarol versus clinical dosing. Results: Pharmacogenetic dosing increased costs by €33 and QALYs by 0.001. The incremental cost-effectiveness ratios (ICERs) were €28,349 and €24,427 per QALY gained for phenprocoumon and acenocoumarol respectively. At a willingness to pay threshold of €20,000 per QALY, the pharmacogenetic dosing algorithm was not likely to be cost-effective compared to the clinical dosing algorithm. Conclusions: Pharmacogenetic dosing improves health only slightly when compared with clinical dosing. However, availability of low-cost genotyping would make it a cost-effective option.