Background: Fatty liver occurs due to the excess fat in liver cells. The patient has a fatty liver when fat makes up at least 5% of the liver, benign condition of simple fatty liver usually does not lead to liver damage, while accumulation of large amount of simple fat may lead to scarring, inflammation and fibrosis of the liver. Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease in developed as well as developing countries. The matter of the association between liver disease and diabetes mellitus is surging all over the world. Aim of study:To estimate the frequency and distribution of fatty liver disease in children and adolescents with type 1 diabetes mellitus.Patients and methods: Fifty children and adolescents with type 1 diabetes with mean age 10.5 ± 4.011 in range (3-18) year who were followed up in the diabetic clinic of Children Welfare Teaching Hospital in Baghdad have been examined to detect fatty liver disease, from 1st of June 2016 to 1st of December 2016. History was taken, physical examination was performed, and liver function tests, fasting lipid profile, HbA1C, and ultrasound of the liver were done. And by applying the NAFLD fibrosis scoring formula there were three groups of patients (F0-F2) with no fibrosis, (F2-F3) with intermediate score of fibrosis and (F3-F4) with presence of fibrosis.Results: There were 50 patients with type 1 DM included in this study; thirty females and 20 males. Thirteen (26%) of them have hepatomegaly while 37 (74%) with normal liver size and texture as detected by abdominal ultrasound. According to the result of NFS (NAFLD fibrosis score) formula and abdominal ultrasound, 5 (38.5%) of the patients with hepatomegaly showed presence of fibrosis, 5 (38.5%) showed intermediate score, while 3 (23%) showed no fibrosis which represent the false negative value while the patients with normal liver 27 (73%) showed no fibrosis and 10 (27%) showed intermediate score which represent the false positive value. Conclusion:The study clarified that the prevalence of fatty liver disease among type 1 diabetic patients was 10% depending on abdominal ultrasound, lipid profile, liver enzymes and NAFLD fibrosis scoring formula.