Background: Sickle cell disease (SCD) consists of a group of hemoglobinopathies in which individuals inherit hemoglobin variants derived from single point mutations. Asymmetric dimethylarginine (ADMA) contributes to limiting Nitric Oxide (NO) bioavailability in SCD. The aim of the present study was to assess the level of the Asymmetric Dimethyl Arginine in children with sickle cell. Methods: This cohort cross-sectional study was carried out on 60 children which were divided in to 3 equal groups. Group I: SCD children with sickle retinopathy. Group II: SCD children without retinopathy. Group III: healthy control children who were selected from the outpatient clinic. Results: There was a significant increase in ADMA level among participants withSCD. There was a positive significant correlation between ADMA level and family history as well as the incidence of hepatomegaly. There was no significant correlation between ADMA level and demographic and laboratory parameters except LDH. Conclusions: The level of ADMA is elevated in children with sickle cell anemia. High plasma ADMA level is a risk for hepatomegaly in children with sickle cell anemia.