The goal of this study was to establish cross-network mobile money transfer adoption determinants and performance of small and medium enterprises in Murang‟a municipality. Specifically, the study sought to assess how the government legal framework, individual attributes, technological characteristics, and perceived social influence affects the adoption of cross-network mobile money transfer service and establishing the association between the use of cross-network mobile money transfer service and SMEs' performance in Murang‟a municipality. Three theories namely; Technology Acceptance Model, Actor-Network Theory, and Innovation Diffusion Theory were employed in this study. Descriptive survey design was used to conduct this research. Primary data was obtained through questionnaires from a sample size of 250 participants using purposeful sampling design. Descriptive and inferential statistics with the aid of SPSS were used to analyze data. The results found out that the adoption rate of cross-network mobile money transfer service was very low as only 36 % of the respondents had adopted the service at the time of the survey. Respondents strongly agreed that Individual attributes as shown by the mean of 14.904, Perceived social influence (15.145), Technological characteristics (14.904), and legal framework (14.747) influenced their decision to adopt the service. The study also established that the adoption of cross-network mobile money transfer service had escalated the performance of the businesses as revealed by a majority of respondents (71%) of those who had adopted the service. The study recommends that SMEs traders adopt cross-network mobile money transfer service because of its positive impact on business performance. The study also recommends that policymakers introduce interoperability at the agent level and conduct aggressive marketing to increase the adoption rate of the service. To increase financial inclusivity in the country the study recommends that the service providers raise transaction limits of mobile money to attract more users in Kenya. There is a need to conduct further follow-up studies on the same topic in later years to assess the extent of adoption and also to assess the effect on financial performance of large organizations.