Lithium is widely used in psychiatry to treat bipolar affective disorders since 1970 but little is known about the incidence, clinical course and associated factors of acute lithium intoxication. Moderate and severe cases of lithium intoxication are rare. This case reports a patient with acute lithium intoxication (serum level of 3.7 mmol/L) with neurological symptoms imitating stroke, which affects the differential diagnosis in the pre-hospital and hospital care. Patient was treated with forced diuresis and dismissed 21 days after admission.