Background: Type 1 diabetes mellitus (T1DM) is a chronic autoimmune disorder where the immune system attacks and destroys the insulin-producing beta cells in the pancreas Aim of the study: the study aims to assess Knowledge and attitudes regarding diabetes type 1 among adolescents in nursing secondary school. Research design: Descriptive research design will be used to achieve the aim of the current study. Sample: Convenient sample of nursing secondary. Setting: The current study was conducted at a nursing secondary school in the village of Nasser and Wasti in Beni-surf City. Tool: interview questionnaire sheet about adolescents' social demographics, knowledge, and attitude regarding type 1 diabetes among adolescents. Result: The study illustrated that there was a positive association between the studied students' total knowledge and attitude score p-value (<0.05*), which means increased knowledge positively increases attitudes.Conclusion: There is a statistically significant relationship between the social knowledge of the students studied and their attitude score. Recommendation: Manual handbooks containing essential nursing procedures regarding the care of adolescents with DM1