Spiritual capital is the main driver of dynamism and energy production in organizations, making them have abilities leading to their excellence and sustainable development. Accordingly, the present study aimed to detect factors affecting spiritual capital in non-governmental organizations (NGOs) in Tehran. The study adopted a descriptive (non-experimental) method, and the research design was correlational using structural equation analysis. The statistical population of the study encompassed all NGO employees in Tehran. According to Cochran's formula, 384 persons were selected as the statistical sample of the study by the simple random sampling method. A researcher-made questionnaire was used to evaluate the research variables. Descriptive analysis, correlation analysis, and structural equation analysis were adopted to analyze the collected data. Findings revealed that the positive and significant effect of causal conditions "organizational and group factors" on the main category "axial value" at P <0.01. Moreover, the findings showed the positive and significant effect of "community culture, family environment, religious environment, and social environment" on the strategy of "workplace culture" and the main category of "value-orientedness" at P <0.01. Further, the effect of workplace culture and value-orientedness on the outcomes of "sustainability, job satisfaction, media feedback, increased interest, employee’s efficiency, organizational commitment, satisfaction and peace of mind" was significant at P <0.01.