Today, sustainability has gained significant importance in supply chain management due to its strategic business advantages. Concurrently, industries are facing supply chain sustainability risks emanated from diversified sources. So far, however, literature is scarce regarding sustainability risk assessment. To fill this research gap, this paper presents a real-life case study of the textile industry to identify and quantify supply chain sustainability risks. In this paper, the fuzzy synthetic evaluation method is applied to compute the likelihood of occurrence, amount of impact, risk criticality of each risk factor group, and the total risk. This study finds five risk groups along with twenty sustainability risk factors. The risk groups are listed as ‘supplier’, ‘financial’, ‘social’, ‘transportation’, and ‘environmental’, based on their respective risk criticality values. The top three sustainability risk factors are ‘poor product transportation system’, ‘air, water, and soil pollution’, and ‘factory fire’. The overall risk criticality value of sustainability risks of the case industry is found as approximately high. An objective of this study is to guide practitioners to take the required strategic steps to assess and manage sustainability risks in their supply chains.