Practice of riba is haram in Islam. MSMEs still need to be motivated not to engage in usury, as many of them are unable to obtain their capital from financial institutions, which encourages them to turn to conventional financial institutions or other sources that offer easier access to their financial, even if they get high interest on their financial activities. In addition to the Islamic financial literacy for individual MSMEs, this is being addressed through Islamic finance and business assistance provided by BSI through the UMKM Center. However, the effectiveness of assistance and Islamic financial literacy in increasing the motivation of MSMEs to avoid riba remains to be investigated. This study aims to determine the effect on assistance and Shariah financial literacy in the motivation of MSMEs to avoid riba, understanding riba as an intervening variable, in MSMEs assisted by BSI UMKM Center Yogyakarta. The research method used is a quantitative method with a survey technique using questionnaires given to 66 respondents who are MSME partners of BSI UMKM Center Yogyakarta. The technique used in data analysis is Structural Equation Model (SEM) using SmartPLS software. Based on the results of this study, it is shown that MSMEs' understanding of riba plays a significant role in increasing their motivation to avoid the practice of riba. Understanding of riba is positively and significantly influenced by Sharia financial literacy. Meanwhile, understanding of riba and motivation to avoid riba are not significantly influenced by the assistance programme. As an intervening variable, the influence of Islamic financial literacy on MSME motivation is strengthened by understanding riba, but the relationship between the assistance programme and MSME motivation is actually weakened by it. Therefore, the BSI UMKM Center needs to pay more attention to helping MSMEs avoid the practice of usury.