Coordination compounds play a vital role in biological systems. Chlorophyll, the pigment responsible for photosynthesis, is a coordination compound of magnesium. Haemoglobin, the red pigment of blood which acts as oxygen carrier, is a coordination compound of iron. Vitamin B12 (cyanocobalamine), the anti-pernicious anaemia factor, is a coordination compound of cobalt. Enzymes like carboxypeptidase A and carbonic anhydrase are other biologically important compounds with coordinated metal ions that act as catalysts in biological systems.

Coordination compounds find many applications in medicinal chemistry. Vitamin B12 (cyanocobalamine) is a coordination compound of cobalt that serves as the anti-pernicious anaemia factor, essential for treating pernicious anaemia.

Coordination compounds play an important role in extraction and metallurgy of metals. For example, impure nickel is converted to [Ni(CO)4] (nickel tetracarbonyl), which is then decomposed to yield pure nickel. A variety of metallurgical processes involve the use of coordination compounds.