Little has been published on the rate of prehypertension (HBP) and hypertension (HTN) in children with hematologic malignancies. This study was preformed to determine the prevalence and predictors of HBP and HTN in newly diagnosed acute leukemia and lymphoma patients. Retrospectively, blood pressure (BP) values were followed from admission until normalization in 102 children. HBP and HTN were defined as either a systolic or diastolic value > or = the 90th and 95th percentile BP measurement, respectively. HBP and HTN were identified in 68.6% and 52.9% of children prior to chemotherapy and 78.4% and 67.3% postchemotherapy, respectively. Mean time to BP normalization was 54 days. Only ten children (15% of HTN patients) received antihypertensive therapy. Logistic regression determined that the only predictor for HBP and HTN was the estimated glomerular filtration rate (eGFR) at the time of admission -- every 10 ml/min per 1.73 m(2) increase led to a 16% and 14% decrease in the odds of postchemotherapy HBP (p = 0.02) and HTN (p = 0.03), respectively. A surprisingly high prevalence of BP abnormalities was identified and lower eGFR predicted HBP and HTN in children with newly diagnosed hematologic malignancies. Better recognition and serious consideration for treatment should be given to this cardiovascular abnormality.