| Objectives: Glycated hemoglobin analysis is the gold-standard to guide diabetes management and screening for diabetic ketoacidosis. Though testing for A1c is a recommendation, correlation with ketone levels has been studied using many variables like fasting blood glucose, mean glucose levels, etc. Our study report is an attempt to document blood ketone levels in relation to measured A1c levels. Study Design: This is a retrospective reference lab-based study. Methods: A total of 429,051 adults including 234,121 males and 194,930 females were tested for HbA1c as well blood ketone levels. Measurement for A1c was done using High Performance Liquid Chromatography, while blood ketones were assessed by photometry technology. Results: Outcome analysis was done by assessing for levels of blood ketone across different HbA1c reporting criteria of normal and good control up until the poor control range of >10.0% (86 mmol/mol). Trend analysis to study relation between HbA1c and ketone levels detected, a significant positive association between A1c levels >/= 15.0% (140 mmol/mol) and blood ketone levels. Conclusion: Our report highlights A1c levels of> 15.0% (140 mmol/mol) to be a significant cut-off to identify patients at risk for diabetic ketoacidosis.