Inborn errors of metabolism (IEM) are a group of disorders that may be inherited or may occur as the result of spontaneous mutation. IEM are relatively common disorders in the Middle East and Arabic populations. This study aimed to detect of IEM among high risk infants admitted to pediatric intensive care unit (PICU). Patients and Methods: This was a cross-sectional study was carried out at NICU in Pediatric Department at Zagazig University Children Hospital during the period study 2021. This study involved 60 neonates and children who were subjected to full medical history, thorough clinical examination, and laboratory investigations:serum levels of electrolytes, plasma ammonia, and lactate, urine organic acid analysis, extended metabolic screening, blood gas, and serum anion gap and blood glucose level. Results:The mean age and weight distribution among confirmed IEM cases were 1.7±0.45 and 6.65±3.45. All confirmed IEM cases delivered by CS, had a positive consangioys parents had negative family history of neither previous abortion nor previous genetic or metabolic diseases. Furthermore, 33.3% of studied confirmed cases had positive family history of previous abortion. The main complain were vomiting, encephalopathy and pallor. All cases showed positive CRP while procalcitonin was positive in 66.7% of cases. About 66.7% of confirmed IEM cases had metabolic acidosis. The hyperammonemia was detected in 66.7% of the confirmed IEM cases. The frequency of Hypoglycemia was detected in 33.3% of the confirmed IEM cases. About 66.7% of confirmed IEM cases had positive blood culture.Conclusion: Extended metabolic screen is helpful in diagnosis of a significant group of treatable IEM. So, early detection and early intervention to the neonates at risk of IEMs before the onset of symptoms can prevent or reduce serious neurological and developmental squeal.