P enicillium marneffei ( P. marneffei ) is a facultative intracellular pathogen and the only thermally dimorphic fungus. This fungal infection is commonly found in Southeast Asian, Hong Kong, south China, and especially in acquired immunodeficiency syndrome (AIDS) patients. 1-4 We reported a patient with AIDS in whom infection due to P. marneffei was demonstrated. CASE REPORT A 34-year-old man with human immunodeficiency virus (HIV) infection (diagnosed before 6 months), living in Guangzhou of south China, was admitted to the hospital because of prolonged fever, cough, and weight loss. Initial examination revealed permanent high-grade fever (39-40℃) with chill and cough. Laboratory findings revealed haemoglobin concentration at 80 g/L, CD 4 lymphocyte count at 7×10 6/L, and viral load at 1.3×10 5 copies/ml. Blood and urine culture revealed no bacterial growth. Sputum culture was negative for mycobacterium. Chest X-ray film revealed left upper lobe ill-defined parenchymal opacities and widening of the superior mediastinum with left lung hilum prominence (Fig. 1). Abdominal B ultrasound showed hepatoplenomegaly and coeliac enlarged lymph nodes. On physical examination, the patient was found to have facial papula, cervical and superclavicular multiple lymph nodes.