Introduction: As searching and perceiving various aspects of human being are impossible by quantitative methods, it is important to use qualitative methods for disciplines that study human phenomena. Due to the development of the holistic paradigm in nursing, the naturalistic paradigm has received more attention. It emphasizes holism and is based on nursing philosophy such as structuralist and constructivist approaches which are both suitable for solving nursing problems. However, most articles use them interchangeably. This study aimed to explain structuralist and constructivist approaches. Methods: This review study was conducted via searching certain databases including Google scholar, PubMed, SID, and ScienceDirect using “ constructivism” , “ structuralism” , “ constructionism” , and “ nursing” as keywords both in Persian and English in combination and separately, among published articles. The articles explaining the two approaches were studied. Results: Both constructivism and structuralism are qualitative methods. The structuralist approach makes sense of the background structures of patients. It replaces subjects with anonymous entities, irrespective of time. Constructivism helps to find out socio-economic and political factors of a social problem, emphasizing a construct formed in the observer’ s mind. Both approaches are holistic and provide deeper understanding. They are used in most articles interchangeably, though. Conclusion: Constructivism and structuralism, as approaches of naturalism, result in grasping human reaction, motivation, and feelings. They are appropriate approaches to unveil complex problems of health in nursing and detect the structures behind social realities. However, they are different in some respects such as the school of thought, the role of the researcher, and the purpose of data analysis.