The antiseizure medication levetiracetam is used to treat epilepsy with significant success, the medication concentration in serum may be affected by other co-administered medication. Levetiracetam is excreted renally, and the halftime is depending on the renal function which is often correlated to age. The clinical chemistry laboratory at Sundsvall hospital did previously send samples for levetiracetam analysis to Karolinska University Hospital in Stockholm. There was a wish to start analysing the medication locally to reduce analysis time and thereby increase patient safety. ARK Diagnostic markets a kit for quantitative analysis of levetiracetam on automated chemistry analysers. The sample may be taken in a few different test tubes with slightly different characteristics. The aim of this study was to verify the ARK kit on Cobas Pro c503 at Sundsvall hospital and investigate the effects of different test tubes. To assess the accuracy and precision of the method, serum was spiked with levetiracetam from a liquid solution to construct dilution series for testing linearity and sample materials, and by running internal controls to assess the repeatability and reproducibility of the method. The results show that the method does in fact give accurate measurements of the levetiracetam concentration and the results does not vary more than acceptable between measurements nor over time and that different sample type does not show a clinically important difference in result.