Abstract Introduction Hyperglycemia occurs in Acute Lymphoblastic Leukemia (ALL) due to chemotherapeutic agents and may be stress-induced. Given the potential impact of hyperglycemia on the clinical outcomes of ALL patients, we sought to determine the association of hyperglycemia with the development of infectious complications. Methods This is a retrospective cohort involving adult Filipino ALL patients admitted at a tertiary referral center. Patients were stratified according to blood glucose levels and infections were classified into microbiologically and clinically defined infections. Logistic regression was performed to determine whether hyperglycemia was associated with the development of infectious complications. Results Of the 174 patients admitted for ALL, only 76 patients (44%) underwent blood glucose monitoring and were thus included in this study. Hyperglycemia was observed in 64 patients (84.21%). Infectious complications were seen in 56 patients (73.68%), of whom 37 patients (48.68%) had microbiologically defined infections and 19 (25%) had clinically defined infections. The respiratory tract was the most common site of infection and gram-negative bacteria were the predominant isolates. Hyperglycemia significantly increased the likelihood of infectious complications, particularly at blood glucose levels ≥ 200 mg/dL. Conclusion Hyperglycemia is associated with an increased likelihood of infectious complications in Filipino ALL patients. With sepsis being one of the main causes of mortality in this population, our study provides compelling evidence for us to consider routine blood glucose monitoring in order to manage and potentially decrease the occurrence of infections in these patients.