Public Relations profession, as it is for other professions has not been left behind in embracing social media technologies. With the contemporary globalization trends, Public Relations activities are also skewed towards the need of the changes with global diverse customers’ – the netizens. Since Public Relations Agencies are considered as bridge to local and global corporations in executing Public Relations Agencies, this study highlighted the Tanzanian and Turkish Public Relations Agencies’ activities, key clients and their engagement in social media – a comparative study, guided by Diffusion of Innovation Theory (DOI). Profiles of six purposively sampled Public Relations Agencies - three from both countries were analysed using descriptive method. Content analysis was then used to analyse the firms’ activities/strategies and social media engagement. The firms’ official social media accounts were scrutinised in grasping their engagement to social media. All available required information was collected and analysed from the three Social Networking Sites (SNSs) which were purposively sampled as the mostly used SNSs in the world, namely; Facebook, Twitter, and Instagram. The findings identified Public Relations Agencies from countries, their activities and clients. Similarities and differences have been shown between the agencies in the two countries rooted from the countries’ profiles. Public Relations Agencies from Tanzania and Turkey exercised professional duties while some include other related tasks - witnessing those in Turkey having more exposure due to the presence of market competition led by one among the Global Public Relations Agencies. In social media engagement (social media innovations) – posts/tweets, followers, following, and likes revealed that Public Relations Agencies in Turkey have more engagement compared to those in Tanzania – chiefly due to economic and science and technological development and hence are in more favourable position in reaping from the digital age. While this study suggests more efforts for awakening Public Relations profession in Tanzania to be taken into consideration, the same has been suggested in Turkey as to suit the global terrain. Lastly, the researcher decided to arrange all tables before the references list to avoid monotony as 13 tables were created during the study. They have been cited where details might be in need.