Background: Pediatric onset Systemic lupus erythematosus (P-SLE) is an autoimmune multisystem illness with disease occurrence before the age of eighteen. It is a highly complicated condition with a significant variability across individuals. Aim of the study: To assess hematological parameters in P-SLE patients attending to the Pediatric Rheumatology out-patient clinic in Minia University Children Hospital, as well as, admitted to the in-patient ward and to evaluate the relationship between these hematological parameters and activity of P-SLE disease. Methods: This study was a prospective cross-sectional study included 40 children diagnosed with SLE attending to the Pediatric Rheumatology out-patient clinic in Minia University Children Hospital, as well as, admitted to the in-patient ward, from August 2020 to January 2022. Also, 40 apparently healthy children were included as a control group. They are age and sex matched, with the children having SLE. All enrolled Patients were subjected to: Detailed history taking, complete clinical examination, laboratory investigations including:  complete blood count (CBC)  Results: Both Patients with mild disease activity and Patients with moderate to high disease activity had significantly lower hemoglobin level than controls (P= 0.004 and 0.04 respectively), but there is non significant positive correlation between Hb level and SLEAI score as r = 0.382 and p = 0.142. Conclusion: Children having Systemic lupus erythematosus are more likely to have lower hemoglobin level than healthy children which may result in high morbidity in P-SLE, but lower hemoglobin level may not be closely associated with P-SLE disease activity.