This paper empirically investigates the association of quality information provided by a government agency on social media and citizen's online political participation. It further answers the why and how questions regarding the existence of this relationship by examining the mediating influence of transparency, trust, and responsiveness. The data was collected from 388 followers of the social media platforms of a government agency i.e. Punjab Food Authority and the findings of the analysis were obtained using structural equation modeling technique. The results reveal that the agency's provision of quality information on social media was significantly related to perceived transparency, trust in agency, perceived responsiveness, and citizens' online political participation. Moreover, the results show that perceived transparency mediates the relationship between agency's provision of quality information on social media and citizens' trust in agency. Additionally, trust in agency was an insignificant predictor and perceived responsiveness was a negative predictor of citizens online political participation, Also, trust in agency and perceived responsiveness suppressed the relationship between agency's provision of quality information on social media and citizens' online political participation. This study aims to bring awareness and contribution to the body of knowledge about the governmental use of social media and its resulting benefits since in developing countries like Pakistan the research in this area is sparse. Further, it provides strategic and practical suggestions to agencies regarding advantages of utilizing social media in their communication with citizens.