<p>The complement system is a&#xa0;central component of the innate immune system. Dysregulation of this system causes the development of various kidney diseases and numerous other organ manifestations. In recent years the understanding of the underlying pathophysiology of many diseases has substantially increased. Therefore, it is now possible to specifically diagnose and influence the treatment of complement-mediated diseases. This article focuses on the role of the complement system in systemic kidney diseases and highlights how currently approved therapeutic drugs modulate complement activity and restore the immunological balance. In addition, this article presents an overview of the broad spectrum of complement inhibitors currently in advanced stages of clinical development. In the near future the approval of further inhibitors is anticipated, which can also broaden the treatment options for further diseases. Important safety considerations must be taken into account: because the activated complement system is essential for host defense and the clearance of infectious pathogens, its pharmacological inhibition increases the risk of infections with encapsulated bacteria. Consequently, in many cases vaccination against <i>Neisseria meningitidis</i>, <i>Haemophilus influenzae</i> and <i>Streptococcus pneumoniae</i> is mandatory prior to Treatment with most complement inhibitors.</p>