Recent developments of new generations of mass spectrometers and improvements in the field of chromatography have revolutionized protein analytics. Particularly the combination of liquid chromatography as a separation tool for proteins and peptides with tandem mass spectrometry as an identification tool referred to as LC-MS/MS has generated a powerful and broadly used technique in the field of proteomics. The resolution and sensitivity of state-of-the-art LC-MS/MS systems has reached dimensions allowing not only the analysis of individual proteins but also investigations on the level of complete proteomes. However, the enormous complexity and the extreme concentration range of proteins within typical eukaryotic proteomes are still the major challenge of this technique. This review gives an overview of modern LC-MS/MS based proteomics, describing state-of-the-art chromatography and modern mass spectrometry. Strategies to perform quantitative proteomics will be presented and capabilities as well as current limitations of this innovative methodology will be discussed.