Purpose: The purpose of this study was to define the core components required of nurses to provide quality nursing care to patients and analyze the significance of these components in the hospital's various units to maintain a high level of competence among nurses. Method: The study evaluated 3 categories included 35 subcategories with 148 core components that were derived from literature review and interviews of nursing professionals. The nursing professional category included 18 subcategories with 98 components, the organizational culture category included 4 subcategories with 16 components, and the temperament-attitude category included 13 subcategories with 34 components. The study included 335 nurses with more than one year of hospital experience and measured disparities among different hospital units. The data was analyzed with SPSS-Win 10.0, differing perceptions of the importance of general traits among the participants were measured using standard deviation, and differing perceptions of the importance of professional traits among the participants were assessed using ANOVA and subsequently with the Bonferroni Test. The reliability of the aforementioned research tools were evaluated using the Cronbach's ${\alpha}$. Result: The results of the study were as follows: 1. Among the three categories, temperament-attitude category was perceived to be the most important, followed by nursing professional category and organizational culture category. Among the ten most important subcategories within the three categories, safety and infection prevention as well as responsibility were perceived to be the most important, followed by promotion of physiologic adaptation, document management and presentation, self-control, ethics, observance law, coping with emergency, humanity, and medication. 2. The relative importance of category associated with the core competencies within the hospital unit were as follows : 1) The units that rated nursing professional category as being the most significant were: internal medicine, surgical unit, mother-child unit, emergency room, intensive care unit, and operating room, in that order. 2) The units that rated the organizational culture competencies as being the most significant were: mother-child unit, internal medicine, surgical unit, emergency room, operating room, and intensive care unit, in that order. 3) The units that rated temperament-attitude category as being the most significant were: internal medicine, surgical unit, emergency room, mother-child unit, operating room, and intensive care unit, in that order.