A patient who showed Ekbom's syndrome, i.e. delusions of parasitosis, and also lilliputian hallucination is described. She was diagnosed as senile dementia based on the diagnostic criteria of DSM-III-R and cerebral imaging techniques. When she was 74 years, she felt a mowworm-like wriggle in her stomach and their travels all over her body. When she was 78 years, she saw dressed-up dwarfs dance or march on her abdomen. Since the case showed simultaneously delusions of parasitosis and lilliputian hallucinations, it cannot be denied that she has undetected lesions in the brainstem. In this case, the delusions and hallucinations seem to have occurred as a part of psychopathological signs of senile dementia.