Little is known about the impact of Critical Incidents (CIs) on the lives of ambulance personnel. One-to-one interviews were conducted with 27 participants who had experienced CIs during the previous 12 months in order to: assess the nature and impact of CIs on health and well-being; examine attitudes toward support services; and explore barriers to service use. The results showed that incidents involving children, suicides, and grotesque mutilation were the most distressing. Participants reported a wide range of physical and mental health problems including sleep difficulties, angry outbursts, irrationality and feelings of alienation. Key themes included: low support service uptake due to fears relating to confidentiality and machismo; a perceived lack of concern and support from management; and a need for professional counselling and stress awareness training. Emergency Medical Controllers (EMCs) also reported a number of difficulties unique to their role. The findings suggest that exposure to CIs has a significant impact on health and well-being; this has important implications for recognizing and appropriately addressing the health and training needs of ambulance personnel, including the effective management of Critical Incident Stress.