Purpose – This study examines the effects of institutional trust, price spread, and religiosity on gold investment decisions among Muslim investors and investigates the mediating role of risk perception in explaining these relationships.Methodology – A quantitative, cross-sectional research design was employed using survey data collected from 314 Muslim investors in Lombok, Indonesia. Respondents were selected through purposive sampling, and the proposed research model was analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM) with SmartPLS 4.Findings – The results reveal that institutional trust, price spread, and risk perception have significant positive effects on gold investment decisions, with risk perception emerging as the strongest predictor of investment behavior. Institutional trust, price spread, and religiosity also significantly influence investors’ risk perceptions. Furthermore, risk perception significantly mediates the relationships between institutional trust, price spread, religiosity, and gold investment decisions, indicating that institutional, market-related, and religious factors primarily affect investment behavior through investors’ subjective evaluation of uncertainty.Implications – The findings suggest that Islamic financial institutions and gold investment providers should strengthen institutional credibility, improve pricing transparency, and reinforce Sharia-compliant practices to reduce perceived investment risk and encourage greater participation in gold investment among Muslim investors.Originality – This study extends the behavioral finance literature by integrating institutional, market-related, psychological, and religious factors into a single framework. Unlike previous studies that have examined these determinants separately or primarily in conventional financial settings, this research demonstrates that risk perception serves as the key psychological mechanism linking these factors to gold investment decisions among Muslim investors in an emerging Islamic financial market.