This paper reports the development of a highly sensitive analytical method combining solid phase extraction (SPE) with ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS), for the monitoring of ultra-trace levels of Nnitrosamines in water samples. Under optimized analytical conditions, chromatographic separation was performed in 3 min, in isocratic mode, using an Acquity UHPLC C18 column and a mobile phase consisting of acetonitrile, water, and formic acid (60:40:0.1, v/v/v) at a flow rate of 0.4 mL min 1. Electrospray ionization tandem interface was employed prior to mass spectrometric detection. Good linearity (R-2 >= 0.9987) and low limits of detection (0.04-0.4 ng L-1) and quantification (0.1-1.2 ng L-1) were obtained. The extraction recoveries ranged from 98 +/- 1% to 100 +/- 1% and the relative standard deviations were less than 1.53%. The matrix effect was between 9812 and 100 +/- 1%. The obtained results clearly demonstrate that the developed method is accurate and highly sensitive for the simultaneous determination of N-nitroso-n-propylamine, Nnitrosomorpholine, N-nitrosomethylethylamine and N-nitrosodimethylamine at ultra-trace levels (ng L-1) in different types of water samples. Therefore, this method can be a useful analytical tool for future toxicological, water quality surveillance studies and for the investigation of drinking water quality. (C) 2016 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.