The boundaries between the work and non-work spheres have been challenged through the rapid development of information and communication technology (ICT). Individuals may easily engage in non-work (family and private) matters at work and during working hours. Prior research on emotions at work tends to understand all emotions at work as work related. By studying non-work matters managed through ICT in a diary study, we suggest that emotions at work are triggered both by work and non-work matters. Our research shows that these emotions can be both positive and negative and may come from actual engagement in private matters, or as a response to a need or a demand to address a private matter. Since emotions affect work performance, for example, we suggest that HR and managers take the causes of workplace emotions into consideration when addressing issues related to emotions at work.