Introduction: Hyperglycemic emergencies, including diabetic ketoacidosis (DKA) and hyperosmolar hyperglycemic state (HHS), often recur in patients who have poorly controlled diabetes. Identification of those at risk for recurrent hyperglycemia visits may improve health care delivery and reduce ED utilization for these patients. The objective of this study was to prospectively characterize patients re-presenting to the emergency department (ED) for hyperglycemia within 30 days of an initial ED visit. Methods: This is a prospective cohort study of patients ≥18 years presenting to two tertiary care EDs (combined annual census 150,000 visits) with a discharge diagnosis of hyperglycemia, DKA or HHS from Jul 2016-Nov 2018. Trained research personnel collected data from medical records, telephoned patients at 10-14 days after the ED visit for follow-up, and completed an electronic review to determine if patients had a recurrent hyperglycemia visit to any of 11 EDs within our local health integration network within 30 days of the initial visit. Descriptive statistics were used where appropriate to summarize the data. Results: 240 patients were enrolled with a mean (SD) age of 53.9 (18.6) years and 126 (52.5%) were male. 77 (32.1%) patients were admitted from their initial ED visit. Of the 237 patients (98.8%) with 30-day data available, 55 (23.2%) had a recurrent ED visit for hyperglycemia within this time period. 21 (8.9%) were admitted on this subsequent visit, with one admission to intensive care and one death within 30 days. For all patients who had a recurrent 30-day hyperglycemia visit, 22/55 (40.0%) reported having outpatient follow-up with a physician for diabetes management within 10-14 days of their index ED visit. 7/21 (33.3%) patients who were admitted on the subsequent visit had received follow-up within the same 10-14 day period. Conclusion: This prospective study builds on our previous retrospective work and describes patients who present recurrently for hyperglycemia within 30 days of an index ED visit. Further research will attempt to determine if access to prompt follow-up after discharge can reduce recurrent hyperglycemia visits in patients presenting to the ED.