This study aimed to assess the level of knowledge of nurses about the safety of patients after performing a cardiac catheterization process. Merowe Medical City) from August 2021 to March 2022. The study included 35 randomly selected nurses. 13-question questionnaire was designed and the data was analyzed using statistical analysis (SPSS) and presented in graphic forms. The study showed that most of the nurses (45%) have good knowledge regarding cardiac catheterization, and (8%) have poor knowledge about complications and (11%) of the nurses has poor knowledge of the time required for the patient to remain in bed after the operation. (83%) have knowledge of the time required to remove the cardiac catheterization. The study recommended conducting workshops inside the hospital on the care of cardiac catheterization patients after the operation, and the hospital administration should hold continuous training courses so that the nurses can deal with the cardiac catheterization patient after the operation and provide the best health care.