Background: stress-related mucosal disease (SRMD) frequently occurs inpatients admitted to the intensive care unit. During the first days of life thenewborns are under severe stress and have one or more risk factors forstress related mucosal lesions (SRML) that were known from adult studies.Objectives: To evaluate the frequency, types and risk factors of SRML inneonates treated in neonatal intensive care units (NICUs), and the role ofH.pylori in the development of these lesions. The diagnostic role and safetyof upper GI endoscopy and the frequency of stress related mucosalbleeding (SRMB) were also evaluated.Subjects &Methods: A prospective study was performed on 100 criticallyill neonates treated in NICU in Cairo university children hospital for whomupper GI endoscopy was done and biopsies were taken forhistopathological examination for H. pylori.Results: SRML affect 77% of neonates in the NICU, and SRMB accountsfor 22%. RD, RD put on mechanical ventilation, RD with sepsis, RD withsepsis and ventilation, bleeding disorder, NGT, and the duration of NPOwere significant risk factors for SRML. 3 antibiotic therapy, aminophyllintherapy, and ranitidine therapy were associated with significantly highincidence of SRML. H. Pylori was not a risk factor for SRML.Conclusion: Infants treated in NICUs have a high frequency of SRML thatrelated to many risk factors including mechanical ventilation, RD, andmany other factors. H. Pylori was not a risk factor for SRML in this study.The endoscopic procedure was well tolerated and done without sedation.