This was a descriptive type of cross-sectional study conducted among the registered nurses working in the tertiary level hospitals in Bangladesh. The study was conducted to assess nurses' roles to improve the quality of care of patients admitted in tertiary level hospitals in Bangladesh.Data were collected using a pretested structured self-administered questionnaire. Twenty percent of the respondents of the study, the highest were in the age group of 41-45 years, where only 0.4% of the respondents, the lowest were in the age group of 56-60 years.Finally it can be said that nurses are performing advocacy role to a lesser extent and almost half of the respondents did not have idea about evidence based practice. In planning nursing care every nurse should be involved and nurses should be trained about evidence based nursing and advocacy role. Nurses' should be encouraged for doing nursing research for the improvement of the quality of patient care.