The aim of this study was to investigate the effect of self-reported workplace bullying on depressive symptoms in a prospective study among a representative sample of employees from Germany. We focused specifically on the role of the perpetrator (co-workers and superiors), which was never done before in a longitudinal design. We used data from a nation-wide representative panel study with a 5-year follow-up (N = 2172). Data on bullying exposure were obtained separately for different perpetrators (co-workers and superiors) and degree of severity (severe bullying, i.e., at least weekly). Depressive symptoms were assessed with the Patient Health Questionnaire (PHQ). We used logistic regression analyses to examine the effect of workplace bullying at baseline on depressive symptoms at follow-up. After adjusting for baseline depressive symptoms, severe bullying by co-workers significantly increased the 5-year risk of depressive symptoms (OR = 2.50). Severe bullying by superiors had a nonsignificant effect. Workplace bullying is a risk factor for depressive symptoms among employees in Germany. The type of perpetrator seems to be an important factor to consider, as indicated by the elevated risk of depressive symptoms when bullying is perpetrated by co-workers.