Hydroxyapatite with the chemical formula Ca 10 (-PO 4 ) 6 (OH) 2 is an important bioceramic well known for its high osteoconductive properties, non-toxic nature, high bioactivity and good biocompatibility. Moreover, it is known to mimic natural bone. Inspite of the above mentioned advantages, it has certain disadvantages such as having poor mechanical properties, being brittle, not showing an inhibitory effect on microbes and taking a long time to resorb in the body. These disadvantages can be covered up by the addition of dopants which include cations, anions and polymers. These are sufficiently known to improve the properties of hydroxyapatite. This review focuses on the substitution of hydroxyapatite with silver, zinc, magnesium ions and alloys to show the changes in the morphology and biocompatible properties of hydroxyapatite after substitution of the ions in the matrix.