The purpose of this study was to further understanding of nursing applications of uncertainty by analysing the concept of uncertainty as related to illness. From an analysis of the records on uncertainty, the following 4 characteristics of uncertainty were identified: vagueness, complexity, inadequate information and unpredictability. Identified antecedents were internal factors of personality and external situational factors. Consequence were negative responses in the cognitive evaluation area. Empirical referents were the degree of perceived uncertainty with emotional responses and social responses. From this study, nurses can understand the process and degree of perceived uncertainty and this understanding will facilitate the development of a new intervention method for patients and their caregivers.