Hemeproteins are widespread in all groups of living organisms, both as components of key biological processes as well as in very specific metabolic pathways. By variation of either the heme porphyrin structure or the heme protein environment, the function and behavior of the hemeproteins may vary drastically, allowing its role in the most diverse processes. In this short review, selected examples of hemeproteins from anaerobes will be presented, aiming to show the basic, common features of these family of proteins, as well as their diversity in terms of function and composition.