Carcinomatous meningitis (CM) is a rare but serious complication of both solid organ and haematological malignancies. We present a 63-year-old male patient with newly diagnosed peripheral T-cell lymphoma and a new onset presentation of an isolated right 6th nerve palsy. Computed tomography and magnetic resonance imaging did not show any intracranial abnormalities, infarction, abnormal enhancement or haemorrhage. A lumbar puncture was performed due to persistent symptoms, and CSF flow cytometry showed cerebrospinal involvement. He was treated with systemic and intrathecal chemotherapy but succumbed to his illness. This case illustrates a rare but specific finding of CM as cranial nerve VI palsy in a patient who did not have any significant imaging findings. Diagnosis of CM is multimodal and requires a high index of suspicion, early recognition is needed to improve the patient’s quality of life, prolong survival and prevent further neurological deterioration.