The first detailed report of a specific interaction of CP (caeruloplasmin) with another protein described its complex with LF (lactoferrin) in 2000. Since then, several protein-protein interactions involving CP have been reported, mostly concerning iron-containing proteins. The CP-LF complex was studied thoroughly, and evidence of reciprocal effects of CP and LF was obtained. Another specific interaction investigated in detail occurs between CP and MPO (myeloperoxidase). CP-LF, CP-MPO and CP-LF-MPO complexes were found in sera of patients with inflammation. Modelling in vitro allowed understanding of which structural peculiarities of CP and partners allow the modification of their functions in a complex. The present paper reviews the latest data on complexes of CP with LF and MPO, and advances some suggestions about their role in health and disease.