Diagnosis of aminoacidopathies constitutes a challenge in a developing country with high positive consanguinity rate and no newborn screening programs. The number of diagnosed inborn errors of amino acid metabolism is growing constantly due to the availability of recent analytical technique as tandem mass spectrometry (LC/MS/MS). This study highlights the importance of clinical awareness among physicians in patients presenting with unexplained neurological signs and alarming features that are commonly associated with metabolic diseases. Our scope is an assessment of overall prevalence rate of amino acid inborn errors metabolism in Genetics Research Unit, Pediatric Hospital, Ain shams University. Results indicate that 851 patients with phenylketonuria (PKU), 109 patients with maple syrup urine disease (MSUD), 15 patients with nonketotic hyperglycinemia (NKH), 14 patients with tyrosinemia, 4 patients with homocystinuria, 4 patients with citruillinimia and 3 patients with arginimia. It is clear that high consanguinity rate among families in different types of diseases that 1st cousin consanguinity is the highest rate among patients.