Clinical decision-making and judgment is an essential skill that should be acquired by nursing interns. However, many studies reveal that a large proportion of nursing interns have difficulty in meeting the basic expectation of clinical decision-making. This article begins with a brief review of some theories related to clinical decision-making. Then it takes a case, for example, to show how the wrong decision is made. Furthermore, it makes a general analysis on the case drawing on the concept of bounded rationality, dual-process model, and skills acquisition theory. This article ends with some reflections from the case, to improve the consciousness and skills in decision-making for nursing interns.