Tobacco-specific nitrosamines (TSNA) are harmful and potentially harmful constituents (HPHCs) found in tobacco products. In an effort to standardize quantitative analytical methods for TSNA analysis and reporting, CORESTA has published reference methods (CRM) for the determination of TSNAs in tobacco (CRM No. 72) and tobacco smoke (CRM No. 75) utilizing liquid chromatography tandem mass spectrometry (LC-MS/MS). The objective of this work was to develop an improved method for the determination of TSNAs in tobacco and tobacco smoke using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The application of a UPLC system combined with the new generation mass spectrometers facilitated improved resolution, more rapid analysis, and greater sensitivity. This method utilized a UPLC column with sub 2-micron particle size that offered higher chromatographic resolution for TSNAs, minimized sample matrix effects and reduced analysis time. All requirements for method validation were met including linearity, accuracy, precision, limits of detection (LOD), limits of quantitation (LOQ), method robustness, and standard and sample extract stability. For example, the linearity was demonstrated for all analytes with a coefficient of determination of R²>0.995. The recoveries for all analytes were within 85%-115%. For tobacco analysis, the LOQ (based on lowest calibration standard) for N-nitrosonornicotine (NNN), N-nitrosoanatabine (NAT), and 4-(N-Methyl-N-Nitrosamino)-1-(3-Pyrridyl)-1-Butanone (NNK) was 162 ng/g and the LOQ for 4-nitrosoanabasine (NAB) was 40 ng/g. For smoke analysis, the LOQ for NNN, NAT and NNK was 8 ng/cig and the LOQ for NAB was 2 ng/cig. We also established criteria for the migration of the TSNA methods from LC-MS/MS to UPLC-MS/MS. It was also demonstrated that there is no need for sample clean up using solid phase extraction (SPE), a costly and time-consuming step. Results for this improved TSNA method using UPLC-MS/MS correlated well with results obtained from CORESTA recommended methods (CRM Nos. 72 and 75).