This study focuses on Management Information System (MIS) Adoption in Microfinance Banks (MFBs) in Oyo State, Nigeria. Specifically, the study analyzed factors influencing the adoption of MIS in microfinance banks. Primary data was collected with the aid of administered questionnaire on some selected microfinance banks staff. Data collected were analysed using descriptive statistical tools to determine factors influencing adoption of MIS in Microfinance banks’ in Oyo State, Nigeria. While inferential statistical tools of Multiple Regression and ANOVA were used to determine factors with significant contributions to MIS adoption and at what degrees. Results revealed that Relative advantage- the extent to which a technology provides improvement over currently available tools, Complexity- simplicity of the technology’s use or learning, and Compatibility- consistency of the innovation with social practices and norms among its users were the significant factors that influenced adoption of MIS in Microfinance Banks and were significantly different from one another. It is thus recommended that Common management information system platform should be recommended to all Nigerian microfinance banks by the regulatory authorities for suitable MIS adoption.