The author of the dissertation chose to make the assessment of organizational culture in the context of socially responsible organizations because, supposedly, the organizational culture and the corporate social responsibility, makes impact on the performance of an organization. Implemented the aim of the dissertation: to make the assessment of the organizational culture of socially responsible organizations by means of the developed diagnostic instrument for the organizational culture assessment in socially responsible organizations. The validation of the methodology and the developed diagnostic instrument for the organizational culture assessment would help socially responsible organizations to gain a better understanding of the phenomenon of organizational culture and would facilitate its assessment and use for organizational development. On the basis of the performed analysis of organizational culture instruments, the key criteria of the organizational culture assessment that encompass all constituent elements of organizational culture have been identified, although these elements were not included in the majority of the analyzed instruments. On the basis of the discerned criteria, a diagnostic instrument for the organizational culture assessment in socially responsible organizations has been developed and validated. Both the qualitative and quantitative research methods were applied in the present doctoral dissertation to make the organizational culture assessment in the context of socially responsible organizations. Analysis of documents of 44 socially responsible organizations was performed in the course of the organizational culture assessment conceptualizing the organizational culture of socially responsible organizations. The methodology of the research on the organizational culture assessment in socially responsible organizations has been developed on the basis of quantitative research, detailing the methodological framework of the research, the parameters, and the consistency of the research. The developed methodology allows one to assess and to compare organizational cultures in the context of socially responsible organizations.