We analysed all patients < 18 years of age diagnosed with inborn errors of metabolism (IEM) in the Metabolic Division, Sultan Qaboos University Hospital, Muscat, Oman from June 1998 to December 2000. A total of 82 patients from 76 families were studied, of whom 33 (40%) were aged < 1 week at presentation. Disorders identified included different lysosomal storage disorders (22), organic acidurias (9), carbohydrate metabolic disorders (9), congenital lactic acidosis (9), urea cycle disorders (8), amino acidopathies (8), fatty acid oxidation defects (7/82) and various other miscellaneous disorders (10). Tandem mass spectrometry helped in the diagnosis of 26 (32%) cases. Parental consanguinity was twice as frequent in the study patients as in the general population. Duration of follow-up ranged from 1 to 30 months (median 15) during which time 46/56 (82%) patients with disorders amenable to specific dietary and drug therapy available in Oman were free from frequent exacerbation. Our study shows the relevance of identifying patients with IEM in Oman and the need to establish screening for the conditions identified and provide effective management protocols.