Abstract It was noted recently that the professional practice of social work with clinical micro-units (individual, family, and group) approach uses qualitative research methods in the process of data collection, analysis and interpretation to achieve the desired change. Qualitative research methods seek to examine the intrinsic nature of human phenomena as they are, so that they are based on the subjective dimension of human experience which is constantly changing according to the facts of time and space. This research indicates that when the clinical social work begins in terms of the client, it looks at the client as part of the environmental context in which he exists, and this corresponds to the qualitative research approach which is based on understanding the human phenomena (psychological and social) in their normal environment. This study is also trying to clarify by comparing the similarities and differences between the methods of qualitative research and the professional techniques used by the social worker in the professional practice of clinical social work. As well as, the results of this study can contribute to the provision of alternative criteria for the standards of quantitative approach and more effective in studying the psycho-social phenomena. Keywords: qualitative research methods, clinical professional practice techniques, clinical social work, characteristics of qualitative research, naturalistic inquiry.