Social media tools serve as platforms for the mutual exchange of opinions, impressions and experiences. Increased professional interest in the use of these tools, which are primarily used privately, has led to a blurring of borders between private and working life and to a disruption to the Work-Life-Balance. This thesis examines the extent to which the professional use of social media tools for project teams has become embedded into private life and whether and to what extent the Work-Life-Balance has been influenced. Through empirical analysis, information will be provided about which social media tools are used and whether companies have implemented policies to deal with this subject. For this study an online questionnaire answered by 122 people was created. The results present a bad worklife- balance even though 70% of the respondents consider their current balance between work and private life to be positive. All of them accomplish rather private issues during their leisure. Social media tools do not have a significant impact in terms of the reduction of work-life-balance. However the subjective sensation is distorted by the importance of career to the individual.