Objectives: Diabetic ketoacidosis (DKA) represents a metabolic stress whose treatment induces a systemic proinflammatory cytokine profile and accentuates life-threatening acute complications. The present study determined whether serum levels of the major inducible 70-kDa heat shock protein (Hsp72), a modulator of cytokine expression, were influenced by DKA and its treatment. Design and methods: Serum levels of Hsp72 and glucose were measured in five adolescents with type 1 diabetes mellitus (T1DM) prior to, during and following correction of severe DKA. Samples from nine relatively euglycemic T1DM patients served as controls. Results: DKA pre-treatment samples showed significant elevation in Hsp72 (40.8 ± 6.9 ng/ml) relative to euglycemic T1DM controls (33.6 ± 3.2 ng/ml) (P < 0.05). Treatment resulted in a decline in Hsp72 to control levels within 24 h, with Hsp72 and glucose levels being tightly correlated (r = 0.9258). Conclusion: Extracellular Hsp72 is increased by DKA, paralleling changes in serum glucose levels.