Pyrazolo[3,4-d]pyrimidine is a bicyclic hetero organic nucleus that encompass a pyrazole ring fusion with a pyrimidine ring. It was initially synthesized and evaluated as adenosine nucleoside analogues for cancer and viral therapy. Recently, designing drugs with pyrazolo[3,4-d]pyrimidine nucleus as pharmacophore encourage different biological activities. This bibliographic development presents an overview on works carried out on pyrazolo[3,4-d]pyrimidine derivatives during the period 2017-2021. There were different reported procedures for synthesis of pyrazolo[3,4-d]pyrimidine either by using its main precursors pyrazole or pyrimidine ring as starting materials or by other miscellaneous routes such as one pot synthesis or Diel's alder reaction. Also, the predicted biological activity of pyrazolopyrimidine nucleus was recorded and the results revealed the ability of pyrazolopyrimidine ring to be active against many cancer cells beside its significant anti-inflammatory, antimicrobial, antimycobacterial, antimalarial, antiviral, anti-gout and anti-diabetic activities. Anticancer activity is the most common use of pyrazolopyrimidine ring through inhibition of different targets and different enzymes that play an important roles in cancer development.