Introduction & objectives: Recently, educational psychologists and other scholars question the validity of defining learning mainly as the transfer of information from teacher to the learner. Instead, they emphasized the role of teachers in developing intellectual skills in the learners. The article is an attempt to review studies about critical thinking and to explain the concept of critical thinking, its components, its instruction and its importance in nursing. There are many definitions about critical thinking. Some prominent critical thinking theorists include faction, Watson and Glaser, MC peck and so on.A critical thinker must have certain abilities and characteristics in order to develop critical thinking, teachers can use case studies, brainstorming in writing, question-raising methods for their students. There are a lot of reasons to use critical thinking in health care systems. One of them is the ever increasing amount of data in this field. Critical thinking is one of the crucial skills that is required for the development of nursing education and practice. However, the application of this concept brought about a kind of confusion which emerges when this term is substituted with one of its components such as problem- solving.This study, nine articles and three books were examined.As it is the time of information explosion and scholars need to have access to a great deal of information in a limited period of time, it is a matter of greet urgency to develop intellectual skills such as how to think scientifically.The great revolutions in science and technology have also affected the health care systems including nursing profession. To cope with such changes, the scholars must equip themselves with the essential knowledge as skills, among which critical thinking skills are of great importance.