Hyperglycemia during induction chemotherapy for childhood acute lymphoblastic leukemia (ALL) has been inconsistently associated with risk of infection. We investigated the incidence of hyperglycemia during induction for childhood ALL in a retrospective cohort study of 144 patients treated on a single national protocol (UKALL2003) and explored its association with infection. All patients received dexamethasone. Overt hyperglycemia was seen in 36% and proven bacterial or fungal infection was most common in this group (OR 4.1 (1.1–15.6), P = 0.039). Both hyperglycaemia and infection were particularly common in patients with Down Syndrome. Pediatr Blood Cancer 2013;60:E157–E159. © 2013 Wiley Periodicals, Inc.