In this paper we present an FDA validated method to analyze ten antiarrhythmic drugs (atenolol, bisoprolol, carvedilol, diltiazem, flecainide, lidocaine, metoprolol, propranolol, sotalol and verapamil). A simple and fast sample preparation protocol with protein precipitation followed by ultra performance liquid chromatography (UPLC) for chromatographic separation and mass spectrometric detection applying electrospray ionization (ESI+) and selected reaction monitoring mode (MS/MS) was used. Only 50 μl plasma sample is needed for the simultaneous quantification of all compounds within a 5 min run-to-run analysis time. Sotalol-D6, carvedilol-D5 and verapamil-D6 were used as internal standards.The method was validated according to the FDA guidelines. Correlation coefficients were higher than 0.998 for all compounds. Intra- and interday accuracies were within 15 CV(%) for all analytes.The method is currently successfully applied for routine analysis in our hospital.