A Case of acquired eosinophilic lung complicated with meningoencephalopathy is presented, and clinical and etiological aspect are briefly reviewed. A 35 years old woman was admitted with complaint of headache, stiffneck and anxiety and cough with bloody sputum. (3 rd admission) On the physical examination, there was ho specific finding except stiffneck. Laboratory examinations revealed white-cell count of 7,100, with 37% eosinophils. (87% eosinophils on the 2nd admission) On the spinal puncture, the pressure was 196 mm H2O and the fluid was the clear but the total protein was 184.5 mg/dl and the white-cell count was 470, with 48% eoosinophils and 52% lymphocytes. Skin tests for paragonimiasis and clonorchiasis and examination for stool parasites were negative. The VDRL test was negative and the cold agglutinine, titer was 1:8 X-Ray film of the chest showed irregular streaked densities in the both lung fields and left pleural adhesion. (Left pleural : effusion was 1st admission)) She was placed on prednisolone 40mg daily. And the patient was markedly improved for 15 days admission.