Pegaspargase is a mainstay in the treatment of acute lymphoblastic leukemia. When intravenous (IV) infusion replaced intramuscular (IM) injection as the standard route of administration, there were early reports suggested an increased hypersensitivity reactions (HSRs) rate with IV administration. There have since been eight published reports comparing the incidence of HSRs occurring with IV versus IM pegaspargase. This review analyzes the reports and summarizes their consistent findings where feasible. For grade 3-4 HSRs, the rates are comparable with IV and IM administration. Grade 2 HSRs appear to be more likely with IV than IM administration but the validity of the difference is uncertain. Multiple factors confound the analyses, including the historically controlled nature of the comparisons and the increased likelihood of reporting adverse reactions with IV administration. In summary, the reports do not support the conclusion that pegaspargase-induced HSR rate is more frequent with IV administration.