This paper provides a comparative analysis of Dorothy Orem's Self-Care Deficit Theory and Sister Callista Roy's Adaptation Model in the context of nursing practice. Orem's theory underscores the importance of self-care and the nursing role in addressing self-care deficits, focusing on concepts like self-care agency and deficit. Conversely, Roy's model views individuals as adaptive systems, highlighting the role of nursing in facilitating adaptive responses to environmental stimuli. Through a detailed examination of their theoretical perspectives, assumptions, and key concepts, this analysis elucidates the similarities and differences between the two theories. While Orem's theory concentrates on self-care deficits and the nurse's supportive role, Roy's model takes a broader view, emphasizing adaptation and holistic well- being. Understanding these theories' distinct perspectives can empower nurses to tailor interventions effectively, promoting better patient outcomes across diverse healthcare settings.