A lot of resources are spent on the development of new staff in the intensive care unit (ICU). These resources are necessary because the environment in the ICU is complex and the patients are critically ill. Nurses need an advanced knowledge base, the ability to accurately define and change priorities rapidly, good communication and teamwork skills, and the ability to work in a stressful environment in order to succeed and give their patients quality care. Critical thinking helps the nurse to navigate the complex and stressful environment of the ICU. Critical thinking includes more than just nursing knowledge. It includes the ability to think through complex, multifaceted problems to anticipate needs, recognize potential and actual complications, and to expertly communicate with the team. A nurse who is able to think critically will give better patient care. Various strategies can be used to develop critical thinking in ICU nurses. Nurse leaders are encouraged to support the development of critical-thinking skills in less experienced staff with the goal of improving the nurse's ability to work in the ICU and improving patient outcomes.