Background <p>Dementia with Lewy bodies (DLB) rarely manifests as prominent language impairment. Neurodegenerative nonfluent language deficits are typically recognised as a nonfluent/agrammatic variant of primary progressive aphasia (nfvPPA), which is most often associated with tau pathology and infrequently linked to Lewy body pathology. Herein, we present a rare case of a patient with probable DLB who exhibited marked nonfluent/agrammatic language symptoms and demonstrated language improvement after cholinesterase inhibitor (ChEI) therapy.</p> Case report <p>We describe a rare case of a 71-year-old woman who initially presented with language features suggestive of nfvPPA and was later diagnosed with probable DLB. We assessed her language symptom progression and response to treatment with a ChEI. The patient’s initial symptoms included 4 years of reduced speech output, agrammatic speech, and impaired sentence comprehension, while word comprehension and reading remained intact, consistent with the language profile of nfvPPA. Subsequently, she developed cognitive fluctuations and Parkinsonism. ¹²³I-meta-iodobenzylguanidine myocardial scintigraphy revealed significantly reduced cardiac uptake, though episodes of visual hallucinations and REM sleep behaviour disorder could not be clearly identified. Based on these findings and the diagnostic criteria, the patient was diagnosed with probable DLB with nfvPPA-like language disorder. Treatment with donepezil titrated to 5&#xa0;mg led to an improvement in language function.</p> Conclusions <p>This case underscores the importance of considering Lewy body disease in the differential diagnosis of neurodegenerative language disorders, even when nonfluent speech is predominant. Moreover, ChEIs may offer effective symptomatic treatment for primary progressive aphasia associated with Lewy body disease.</p>