Nowadays, supply chains are highly vulnerable and prone to various risks due to geographical expansion and the complexity of communication networks. Sustainability in supply chains is increasingly seen as part of supply chain management. Sustainability has become a necessity, and every supply chain needs sustainability. However, the supply chain has a breadth and complexity of indicators. This paper aims to provide a model for evaluating the impact of the sustainable supply chain on organizational performance and efficiency in the National Iranian South Petroleum Company (NISOC). This study consists of two quantitative studies and a qualitative stage by designing several questions and using a mixed research method. The qualitative stage uses grounded theory methods following a systematic review of the literature on sustainable supply chain management and its adaptation to the local needs of the sustainable supply chain in one of the country’s largest oil companies. The statistical population of the research includes all employees of the NISOC with an unlimited number, of which 384 subjects are randomly selected as samples. In this study, a questionnaire is used as the data collection tool. The questionnaire designed in this research is based on a 5-point Likert scale. Options range from strongly agree to disagree strongly. The research hypotheses are tested using SmartPLS software. According to the results, the organizational performance and efficiency in the NISOC are affected by the green supply chain, industry supply chain, macro policies, socioeconomic factors, organizational factors, political factors, technology, manufactured products, customers, and supply chain failures. As shown in this study, using sustainable approaches to the supply chain of the petroleum company improves the situation of this organization and increases its effectiveness and efficiency. Further, the performance of individual components of organizations increases due to the sustainability model in this company
