Effective pre-hospital treatment of a person suffering cardiac arrest is a challenging task for the ambulance nurses. The aim of this study was to describe ambulance nurses’ experiences of nursing patients suffering cardiac arrest. Qualitative personal interviews were conducted during 2011 in Sweden with seven ambulance nurses with experience of nursing patients suffering cardiac arrests. The interview texts were analyzed using qualitative thematic content analysis, which resulted in the formulation of one theme with six categories. Mutual preparation, regular training and education were important factors in the nursing of patients suffering cardiac arrest. Ambulance nurses are placed in ethically demanding situations regarding if and for how long they should continue cardio-pulmonary resuscitation (CPR) to accord with pre-hospital cardiac guidelines and patients’ wishes. When a cardiac arrest patient is nursed their relatives also need the attention of ambulance nurses. Reflection is one way for ambulance nurses to learn from, and talk about, their experiences. This study provides knowledge of ambulance nurses’ experiences in the care of people with cardiac arrest. Better feedback about the care given by the ambulance nurses, and about the diagnosis and nursing care the patients received after they were admitted to the hospital are suggested as improvements that would allow ambulance nurses to learn more from their experience. Further development and research concerning the technical equipment might improve the situation for both the ambulance nurses and the patients. Ambulance nurses need regularly training and education to be prepared for saving people's lives and also to be able to make the right decisions.