Consumer Dispute Settlement Agency (CDSA) is an institution that in charge of solving consumer disputes outside the court, one of the CDSA is in South Tangerang City. Due to the short time required to settle in CDSA, mediation dispute resolution is the most appropriate method because it is the fastest method of resolution. The problems examined in this study includes: how is the mediation mechanism used by the CDSA of South Tangerang City in the resolution of consumer disputes and how is the existence of a mediation decision containing a settlement deed against the rights of the parties in filing a civil claim. The purpose of this study is to understand and analyze the mediation mechanism used by the CDSA of South Tangerang City and to find out the existence of a mediation decision in filing a civil claim. This research used Normative-Empirical legal research. This Research prioritizes Secondary Data, Then secondary data is supported by Primary Data. In this study, data were obtained from literature studies and interviews. The approach used in this research tare legal systematics legal cases. In analyzing research results, the analysis used is qualitative analysis. Based on the results of the study, the author obtained an answer to the existing problems, that the mediation mechanism in CDSA of South Tangerang City was carried out through 3 (three) stages, namely the petition stage, the mediation session stage, and the decision stage. The mediation decision containing the settlement deed cannot be appealed to the District Court, nor can it be sued for the default because it has permanent legal force.