This paper discusses two nursing theories, the "Peaceful End of Life Theory" and the "Theory of Human Caring," and their application in clinical practice. The "Peaceful End of Life Theory" focuses on improving the quality of life for terminally ill patients and achieving a peaceful end of life. Its major concepts include pain management, comfort, dignity, respect, being at peace, and closeness to significant others. The "Theory of Human Caring," emphasizes the importance of caring for both the patient and the nurse. It aims to improve nursing practice, education, management, and research. The theories are applied in clinical practice through interventions such as pain management, involving the family in decision-making, and ensuring a peaceful environment for the patient's final hours.