Penicillosis caused by Penicillium marneffei is endemic in Asia and is a highly fatal disease in HIV-AIDS patients. Reports, however; in other immunocompromized diseases are scanty. This report describes the cytological diagnosis of P. marneffei infection from the sputum of a pediatric patient with hypogammaglobulinemia with hyper IgM and severe pneumonia. In this case, rapid, differential identification of the characteristic septated structure of P. marneffei in the macrophages, bronchial epithelium and also extracellularly allowed prompt and proper treatment. In addition, morphometry of P. marneffei obtained from the clinical specimen was reported. This report demonstrated the fungus was not only in the phagocytes, a phenomenon that is well recognized, but also in epithelial cells. Moreover, it also highlights the need for awareness of penicillosis in non-AIDS immunocompromized patients living in, or persons traveling to, P. marneffei-endemic areas.