Mobile Money Services play a key role in aiding financial inclusion for unbanked Small and Medium Enterprises. Despite the fact that Mobile Money Services were introduced long ago in Tanzania, most Small and Medium Enterprises hesitate to adopt Mobile Money Services. This study focused on assessing the influence of perceived usefulness on the adoption of Mobile Money Services among Small and Medium Enterprise in Tanzania. Perceived usefulness included attributes such as time-saving, effectiveness, performance, and business control. A total of 351 respondents (comprised of Small and Medium Enterprises owners and their workers) were administered a well-structured questionnaire. The Statistical Package for the Social Sciences was used to analyse data using both multiple liner regression and binary logistic regression. Results showed that perceived usefulness has a strong influence on the adoption of Mobile Money Services among Small and Medium Enterprises. Additionally, both perceived usefulness attributes, when combined, contribute to the adoption of Mobile Money Services among Small and Medium Enterprises. The study recommended that the government develop policies to ensure the availability and accessibility of mobile money services within the economy's financial system.