Background: Diabetes is chronic endocrine/metabolic disease with heterogeneous etiologies, clinical presentations and associated complications.Its biochemical hallmark is hyperglycemia (American Diabetes Association., 2019)caused mainly by insulin deficiency and/or insulin resistance. Aim of the work: To test the validity of procalcitonin versus other sepsis markers in detection of early sepsis in diabetic ketoacidosis patients and it will impact on thyroid function. Patient and methods: This is a study will be performed in the ICU of Minia University Hospital from May 2020 to May 2021. It will include 30 patients aged from 19 to 42 years old admitted in ICU of elminya university hospital who have diabetic ketoacidosis. The patient include 15 male and 15 female. DKA will be defined as a glucose concentration>300mg/dL, pH≤7.25 or a serum bicarbonate concentration<15mmol/L, and the presence of ketones acetoacetate(either in the blood or the urine). Results: This case control study was performed in the ICU of Minia University Hospital from May 2020 to May 2021. It included 30 DKA patients admitted to ICU of Minia University hospital and 30 controls. The patients age ranged from 19 to 42 years old and included 15 males and 15 females. Table 1 shows clinical and demographic data of studied groups.