The coupling of high-performance liquid chromatography with nuclear magnetic resonance spectroscopy (LCINMR) is one of the most powerful methods for the separation and structural elucidation of unknown compounds in mixtures. The recent progress in pulse field gradients and solvent suppression, the improvement in probe technology, and the construction of high-field magnets have given a new impulse to this technique which has emerged since the mid-1990s as a very efficient method for the online identification of organic molecules. It took nearly 20 years to establish LCINMR and this long period can be mainly attributed to the intrinsic low sensitivity of NMR. LCINMR represents an interesting complementary technique to LCiUV/MS for online identification of LC peaks. Recent applications have demonstrated its usefulness in various fields of analytical chemistry.