: intensive treatment of adult patients with acute lymphocytic leukemia in adults (ALL) by Asparaginase(LASP/PEGASP) was significantly improved patient outcomes. However, much less information available about asparaginase use and toxicity in adult in comparison with its effect in pediatric populations. This was retrospective descriptive study for 56 leukemia patients fromNasseriahgovernoratetreated by PEG-ASP according to UKALL XIprotocol, between January 2015 and October 2019. The Hb, WBCs count, Blastocyte percent., Absolute Neutrophil Count ANC, platelet count, survival rate,transplantation, chemotherapy regimen, duration, type of asparginase,phase, time from last ASP, events, presentation, recovery and dose, were considered and evaluated. 56 patients with ALL were retrospectively enrolled in this study at median age of 30 years. Males represented 60.7 % compared to 39.3 % females. The majority of patients 14(93%) were in phase I and the remaining in phase II.The best dose frequency was three doses that were enough for 8 patients (54%).10 of 15 patients (67%) did not undergo a transplant, while the remaining did not have to.Finally, 10 patients (67%) were survived and three of them with weakness.15(25%) of 56 patients were suffered from the following complications:CVST 5(33%), DVT 4(27%), Hyperglycemia 3(20%), and 1(7%) patient appeared with pancreatitis, biochemical pancreatitis, andskin rash. also, those patients presented with: seizure 5(33%), swelling 3(20%), polyurea 2(13%) and 1(7%) patient suffering polydipsia, abdominal pain, vomiting, redness, and pain. PEG-ASP is feasible as part of an intensive multiagent therapeutic regimen for adult with ALL. This regimen appears associated with improved outcomes,but there are differences in overall survival of those patients sufferingcomplications and those don’t.