Though in an infancy state, the so-called social enterprise software is a highly promising software application for firms. This software links firms’ enterprise software systems and social software applications, thereby offering a novel and remarkably rapid real-time information transfer, e. g. by combining business collaboration, content sharing and instant messaging into one familiar, easy-to-use interface. Besides this, social enterprise software supports tracking data from customer surveys, commentaries, reviews or user profiles on social networks or blogs, thus enabling firms to identify new customers, new market segments and recent trends. With this specific customer data collected and processed, social enterprise software might even facilitate the development of new products, given that it allows the utilizing firms to observe customer tastes and build up customer profiles. This paper analyzes the determinants of social enterprise software adoption and considers factors like firm size, ICT intensity, human capital or international competitive situation. The analysis is based on recent German firm-level data consisting of German firms from the manufacturing industry and the service sector. We apply a two-step approach by using a bivariate probit model controlling for possible sample selection including a valid exclusion restriction. The results indicate that firms with highly qualified workers, a large share of young employees and international business activity are more likely to adopt social enterprise software. Larger and more ICT-intensive firms and recent innovators also have a higher propensity to use social enterprise software. In addition, firms belonging to the service sector are more eager to implement social enterprise software applications. Robustness checks qualitatively confirm the estimation results of the bivariate probit model.