Hydrocarbon pneumonitis, known also as fire-eater pneumonia, always develops after aspiration of low-viscosity, volatile hydrocarbides. Despite the presence of clear-cut indicators for an infection, it is considered to be an acute pseudoinfectious lung disease. In this article, we report on a relatively rare clinical picture of a 30-year-old man after accidental petroleum aspiration. In addition to the usual clinical and instrumental examinations, we also performed, for the first time, electron microscopic investigations of the BAL specimen. A striking finding was the occurrence of macrophages (40%) with numerous lipoid inclusions that exhibited all morphologic signs of an activation as well as neutrophil granulocytes (33%), lymphocytes (21%), and eosinophils (6%). Despite a large and necrotizing infiltration of the right lower lobe, the clinical course was uneventful with complete recovery.