Background Nurses are the main protectors of goodness, honesty and morality in patient care. Conscience allows nurses to be understanding and careful while they provide patient care. In this research the researcher aimed to determine the relationship between conscientious intelligence levels and caring behaviours of nurses and to determine the factors affecting the conscientious intelligence levels and caring behaviours. Methods This research designed as a descriptive, cross-sectional and correlation study included 314 nurses working at three hospitals in eastern Turkey. The (...) data were collected by the researcher at a time when the nurses were available and not working. Written and oral informed consent was obtained from all the participants. Results A moderate significant positive correlation was observed between conscientious intelligence levels and caring behaviours of nurses. The length of service in nursing, sex and being pleased with the nursing profession were associated with conscientious intelligence levels and caring behaviours. Conclusion At the end of this research, it was determined that nurses with high conscientious intelligence had better caring behaviours. Although it is very important for nurses to be knowledgeable of and competent at providing care, taking their conscience into consideration in the care of his or her patients is more important. If a nurse is not pleased with the nursing profession, his or her behaviour should be monitored when he or she provides care for the patient. Persons without conscientious values should not be accepted into the nursing profession. (shrink)