Vulnerable populations, such as those with limited English proficiency, minoritized race or ethnicity, migrant populations, or patients qualifying for public insurance, may be at higher risk for adverse health events. In this review, researchers sought to identify frequency and causes of diagnostic error of vulnerable populations presenting to the emergency department with cardiovascular or cerebrovascular/neurological symptoms. Black patients presenting with cardiovascular symptoms had significantly higher odds of diagnostic error. Other demographic factors did not show similar associations, nor did studies of patients with cerebrovascular/neurological symptoms.