Social media has opened doors of endless opportunities for businesses at little or 10 cost and over the years social media has gradually been gaining ground in the world. The objective this study was to assess the effect of social media marketing on the sales performance of Micro, Small, and Medium Enterprises (MSMEs) in Nigeria with particular emphasis on the Abuja Metropolis. The survey method was adopted for the study and questionnaires were administered as a method of primary data collection. The data were analyzed by the simple regression analysis method. And the findings revealed that there is a need for social media in business interaction in Nigeria, it is significant effect of social media marketing on the sales performance of MSMEs, social media marketing has A significant effect ont the profitability of micro, small and medium enterprises in Nigeria and there is also a significant impact of social media marketing on consumer purchase decision. The study among other things recommended that Micro, small and medium enterprises should create a social media plan that fits into their goals and objectives, post on social media platforms regularly, build relationships and be professional in their dealings with consumers, to improve on their profitability