Allocation of nursing staff to patient care in our teaching hospital Intensive Care Unit is based on providing the care considered necessary, bearing in mind the experience of the nursing staff and the care requirements of the patients. A detailed study of the nurse:patient ratio over a two month period has been carried out. It was found that there was considerable variation in both hours of care required and hours of care delivered from shift to shift. The study supported the principles used in staff allocation based on professional judgement, namely the acceptance of a high nurse: patient ratio, with other staff available for special duties, administration and education.