The purpose of this research is to determine and analyze whether there is an impact of social media marketing towards the customer satisfaction at PT Mega Wisata Indah, one of the developing travel agencies in Medan. Although they have utilized social media in their marketing, they may have some problems in maximizing the usage, which is the reason why the author has decided to do this research. There are many positive impacts of implementing social media as a company marketing tool. It is well-said by the experts that social media such as micro�blogging, can affect firms’ marketing strategy, branding, and the interaction between customers. In addition, it is also stated that social media marketing can reduce call center costs, enhance brand loyalty and increase customer satisfaction. This research is uses a quantitative data , descriptive and correlational methods as research design. This research is done with a sample size of 54 people which is the customers of PT Mega Wisata Indah. The data analysis methods used in this research include descriptive statistics, validity test, reliability test, normality test,linearity test correlation test, determination test, linear regression analysis and hypothesis test.The result of the research based on Z test (the sample exceed 30), is that the Z Count (5.18) > Z Table (1.96) which proves that here is an influence between Social Media Marketing and Customer Satisfaction. In conclusion, it has been proven that Social Media Marketing has an impact in the Customer Satisfaction at PT Mega Wisata Indah. Therefore, the author has suggestions for the company to improve its social media marketing which will give PT Mega Wisata Indah a favorable impact in their customer satisfaction.