Diabetes-specific knowledge was poor in both patients and primary family caregivers in our largely Latino urban emergency department patient population, highlighting the need for increased education in non-traditional settings. Based on our findings, this education should focus on areas of severe knowledge deficit including diet, symptoms of hyper- and hypoglycemia, and wound care. This study provides the foundation and justification for constructing effective and focused emergency department-based educational materials, thereby improving the knowledge and health of our patients.