To identify the extents of nursing professionalism, clinical decision making abilities and job performance of advanced practice nurses and investigate the relationship among the variables Methods: Participants, selected by a convenience sampling method, were 135 advanced practice nurses working in 4 tertiary care general hospitals in ‘B’ Metropolitan City and in 1 tertiary care general hospital in `J` city. Data collection was done from January 15 to February 28, 2013 using self-reporting questionnaires. Results: The average score for nursing professionalism of study participants was 81.19±7.56. for clinical decision making abilities, 140.42±9.62 and for job performance, 102.54±10.30. These averages are relatively high. The relationship between the extent of nursing professionalism and the extent of clinical decision making abilities showed an intermediate level positive correlation (r=.45, p<.001). The relationship between the extent of nursing professionalism and the extent of job performance was also an intermediate level positive correlation (r=.42, p<.001). The extent of clinical decision making abilities and the extent of job performance was an intermediate level positive correlation (r=.41, p<.001). Conclusion: Developing a program, which can improve nursing professionalism and clinical decision making abilities of nurse, is required to enhance their job performance.