Primary CNS lymphoma is an uncommon form of extranodal Non Hodgkins lymphoma and consists of 2.4 to 3% of all brain tumours and 4 to 6 % of all extranodal lymphomas. The incidence has increased in past two decades in patients aged above 60 years. It can occur in both immunocompetent as well as immunocompromised individuals. The occurence in immunocompetent individuals are associated with diagnostic and therapeutic issues and the management is also different from other extranodal NHL. Primary CNS lymphoma can involve eye and CSF and so diagnostic assessment of these regions are also important.