This study examines the implementation of Sharia business ethics and its contribution to sustainable business performance among Islamic microenterprises. Specifically, it explores how Islamic ethical principles are incorporated into business operations, how ethical practices shape relationships with customers and other stakeholders, and what challenges entrepreneurs encounter in maintaining ethical business conduct. This study employs a qualitative approach using a multiple-case study design. Data are collected through semi-structured interviews, non-participant observations, and document analysis involving purposively selected Islamic microenterprise owners and relevant stakeholders. Data analysis follows the interactive model of Miles et al. (2014), comprising data condensation, data display, and conclusion drawing and verification. The analytical framework focuses on five dimensions of Sharia business ethics: honesty (ṣidq), trustworthiness (amānah), justice (ʿadl), transparency, and social responsibility. The study conceptualizes these ethical principles as an integrated foundation for responsible business management, customer trust, stakeholder relationships, and business continuity. It also highlights potential implementation challenges, including limited managerial understanding, financial constraints, inadequate administrative systems, digital literacy limitations, and market competition. This study contributes to the discussion of Islamic entrepreneurship by connecting Sharia business ethics with the multidimensional concept of sustainable business performance, encompassing economic, social, and ethical responsibilities.