Background:Cardiac surgeries greatly influence the physiologic status of fluid and electrolytes in the body, patients can
experience a many of fluid and electrolyte disorders. So, fluid and electrolyte stabilization is one of the corner stones of
patient's nursing care. Methodology: A descriptive cross-sectional research design was utilized in this study. Setting:
The study conducted at the cardio-thoracic surgery department affiliated to Mansoura University Hospitals. Tools: Tool I
Self-administered interview questionnaires and consisted of two parts Part 1: used to address nurses' demographic data
Part 2: concerned with nurses' knowledge regarding fluid and electrolyte balance. Tools II Observational checklist fluid
and electrolyte therapy. Sample: All available registered nurses in the previously mentioned setting (52 Nurse). Result:
more than half of the studied nurses had unsatisfactory level of knowledge (52%) and about two thirds had adequate
competent practice (62%) regarding fluid and electrolyte balance in cardiac surgery patients with highly statistically
significant correlations between nurses' total knowledge level, and clinical competency scores with their age, gender,
educational level, years of experience, and attendance of training program. Conclusion: This study represents that more
than half of the studied nurses had unsatisfactory level of knowledge and about two thirds had adequate competent
practice with a statistically significant correlations between nurses' total knowledge level, and clinical competency scores
with their age, gender, educational level, years of experience, and training program attendance. Recommendation: This
study recommended that, continuous educational programs on regular basis to improve nurse's knowledge and practice
regarding fluid and electrolyte therapy to achieve high quality of care for cardiac surgery patients.