Purpose: To analyze the factors that influence the intention of Muslims to sustainable modest fashion. Design/methodology/approach: using quantitative methods. The analytical technique used is Partial Least Square-Structural Equation Modeling (PLS-SEM) with 220 respondents as a sample of Muslims in Bandung City, Indonesia. Findings: The results showed altruism, egoism, and Islamic religiosity affect attitudes. Then, altruism value, egoism value, and attitude affect purchase intention. However, Islamic religiosity does not affect purchase intention. Practical implications: Entrepreneurs can incorporate the values of altruism and egoism in their marketing communications. In addition to emphasising environmental and social protection aspects, businesses can pay attention to the aesthetics and quality of their products. Meanwhile, the government can provide support through policies and facilities that encourage the production and consumption of products that are in line with sustainable development goals (SDG’s). Originality/value: This study examines the influence of altruistic values, egoistic values, Islamic religiosity, and attitudes on purchasing intentions in one theoretical framework. This research specifically focuses on one type of fashion product, namely modest fashion, which has not been widely studied in previous research in the realm of sustainable consumption.