Acylcarnitine profi le (ACP) is a useful tool in the biochemical diagnosis and monitoring of many acquired and inherited metabolic disorders. In the present study, acylcarnitines (ACs) were quantifi ed in dried blood spot samples collected from 150 high risk Egyptian newborns and children using LC/MS/MS technique. They were referred to the Biochemical Genetics department in the National Research Center. Their age ranged from 1 to 36 months. Thirty seven patients had abnormal ACP diagnostic of some inherited metabolic disorders and other acquired conditions. The study revealed 5 (13.5 %) with medium chain acyl CoA dehydrogenase defi ciency (MCADD), 1 (2.7 %) with long chain hydroxyacyl CoA dehydrogenase defi ciency (LCHADD), 1 (2.7 %) with multiple acyl CoA dehydrogenase defi ciency (MADD), 28 (75.7 %) with secondary carnitine defi ciency (SCD), 1 (2.7 %) with glutaric aciduria type I (GA I), and 1 (2.7 %) with methylmalonic aciduria (MMA) (Tab. 8, Ref. 39). Text in PDF www.elis.sk. Key words: inborn errors of metabolism, fatty acid oxidation disorders, acylcarnitine profi le, LC/MS/MS.