Continuous renal replacement therapy (CRRT) is commonly used to provide renal support for critically ill patients with acute kidney injury, particularly patients who are hemodynamically unstable. Aim: The study was aimed to assess the level of knowledge on continuous renal replacement therapy in critically ill patient among critical care nurses. Methods: A descriptive correlative study was conducted to assess the level of knowledge on continuous renal replacement therapy in critically ill patients among critical care nurses at selected tertiary care centers. After obtaining ethical clearance and setting permission,100 staff nurses were selected by consecutive sampling technique. The data was collected by self-administration method using predetermined and pretested tools through Google forms in WhatsApp / E mail. Results: The study findings revealed that the majority of the critical care nurses were aged between 21-25 years (73%), graduates (95 %), 40% of them had 1-3 years of total experience and experience in critical care unit and had received the necessary knowledge about CRRT through in-service education (59%).More than half of the critical care nurses had moderately adequate knowledge (51%), 38% of them needed improvement and 11% of them had adequate knowledge on continuous renal replacement therapy in the critical care unit. The mean and standard deviation of knowledge scores on continuous renal replacement therapy in the critical care unit was M= 17/30, SD= 3.93 and mean percentage was 56.66. There was a significant association between background variables like age and level of knowledge on continuous renal replacement therapy in CCU at P< 0.05. Conclusion: The findings from the study contributes that more than one third of the nurses needed improvement on knowledge regarding continuous renal replacement therapy in critically ill patients.