Abstract <p>Magnetic resonance imaging has evolved as an effective diagnostic tool to localize unhealthy tissues which has induced the development of pharma products—contrast agents. Due to their paramagnetism, it increases the relaxation rate of water protons in the surrounding tissues. The porphyrin skeleton has been used for the past few decades due to its unique affinity towards tumor tissues to function in this strategy. Metalloporphyrins like gadolinium and manganese metals with different bioactive groups conjugated to enhance the relaxation time discussed in this review. The various ranges of relaxivity depending on the metal and bioactive ligand that chelated to porphyrin and its potential to cause cancer cell death with different cancer cell lines have been discussed.</p>