This is an unusual case of primary central nervous system lymphoma (PCNSL) with isolated third cranial nerve palsy as the initial manifestation. Neurolymphomatosis (NL) is a rare manifestation of PCNSL. While NL is a rare manifestation of PCNSL, primary vitreoretinal lymphoma (PVRL) can be the presenting feature or a later-involved manifestation. We present an unusual case of PCNSL with the isolated third cranial nerve palsy as the initial manifestation, which mimics the surgical third cranial nerve palsy. The patient developed PVRL subsequently and succumbed to the disease not long after the presentation.