Background: Systemic lupus erythematosus is a chronic, relapsing inflammatory disease that affects both cellular and humoral immunity Aim: This study aimed to assess mothers' knowledge towards systemic lupus erythematosus.Research design: A descriptive design was utilized in the current study. Settings: Thisstudywas conductedatpediatric medical departments in Specialized Pediatric Hospital and Health Insurance Hospital in Benha City.  Subjects:A purposive sample of 50 mothers accompanying their children suffering from systemic lupus erythematosus. Tools of data collection: One tool was used: A structured interview questionnaire formats. Results: There was a highly statistical significant relation between total mothers knowledge level and their age, education with P < 0.001.  Conclusion: Majority of studied mothers had unsatisfactory level of knowledge regarding systemic lupus erythematosus. Recommendations: Continuous educational programs to increase awareness of the mothers having children with systemic lupus to ensure enough knowledge and decrease functional disabilities of the children.