We have developed a LC-MS-based analysis of the cerebrospinal fluid (CSF) metabolome and applied this approach to a cohort of 100 patients with various neurological disorders including patients with suspected neurometabolic disorders and patients with known metabolic disorders. Among these patients, 60 were previously studied by in vitro H-NMRS spectroscopy (Mochel et al., 2009) . From the 36 metabolites previously identified by H-RMNS only 6 could not be found with LC-MS, whereas the latter method allowed the detection of 106 additional characterized metabolites. All patients with abnormal metabolite profiles on H-RMNS were also highlighted with LC-MS but this technique allowed further identification of abnormal profiles in some patients considered normal with regards to H-NMRS.