ObjectiveTo explore the psychological pressure in Intensive Care Unit (ICU) nurses and the sources of their pressure. MethodWe investigated the ICU nurses in West China Hospital with a self-designed psychological pressure questionnaire from March to September 2013. ResultsThe total stress level of ICU nurses was 2.89±0.86. The top five sources were low salaries and welfare benefits (3.37±0.61), high frequency of night work (3.31±0.88), wide need of knowledge (3.22±0.41), heavy workload (3.20±0.80) and chronic fatigue syndrome (3.19±0.75). ConclusionsGreat psychological pressure exists in ICU nurses. We urgently need effective approaches to relieve the stress of ICU nurses in order to improve the efficiency and quality of nursing service.