The objective of this study was to examine Emergency Medical Services (EMS) activation in a cohort of critically ill patients and to evaluate whether factors such as perceived difficulty of access to emergency care, insurance status, and educational level are associated with EMS use. Patients admitted from the emergency department to the intensive care unit (ICU) of an urban county hospital for diagnoses other than acute cardiac conditions or stroke were interviewed about EMS use. Overall EMS use was found to be 52%. Primary reasons for not activating EMS were a belief that symptoms were not serious (36%) or that self-transport was faster (25%). The only factors significantly associated with bypassing EMS were car ownership, lack of health insurance, and self-decision to go to an emergency department. Sixty-eight percent of the sample reported little difficulty in accessing emergency care. In conclusion, because of a belief that symptoms were not serious or self-transport would be faster, nearly half of the critically ill patient sample did not activate EMS. Patient education about warning sign recognition for serious illnesses and about the potential benefits derived from EMS should be improved.