Introduction: The abducens nerve, or cranial nerve six (CN VI), is the most common nerve involved in cranial nerve palsy. Various causes have been identified as the aetiology, but no association has been made with monoclonal gammopathy. We aim to describe isolated cranial nerve palsy in a child with monoclonal gammopathy. Case report: We report a case of a healthy 6-year-old girl who presented with sudden onset binocular diplopia, headache, and unsteady gait. Further investigation revealed isolated left sixth cranial nerve neuritis with monoclonal gammopathy, which was treated with steroids. Discussion: Cranial nerve palsy is an alarming sign, especially in children, and is almost always related to intracranial pathologies such as a tumour, hydrocephalus, and meningitis. Conclusion: Prompt investigations alongside relevant management result in a good prognosis.