Oral hairy leukoplakia (HL) has been regarded as an early sign of HIV infection, and its clinical importance related to the poor outcome of the patients has been emphasized. Initially, HL was observed exclusively among male homosexuals, but subsequently demonstrated in all risk groups of HIV infection. The patient described in this article suggests that oral HL is not specific for HIV infection per se, but may be associated with immunosuppression also due to other causes. We describe an HIV‐seronegative, heterosexual man suffering from an acute myeloblastic leukemia, who developed clinically and histologically typical HL while on cytostatics. Biopsy showed areas with characteristic ballooning cells, and hyphae of yeasts were demonstrated with PAS–stain. Using the in situ hybridization technique, Epstein‐Barr virus (EBV) DNA with high copy numbers was disclosed in the superficial and intermediate cells, whereas human papillomavirus (HPV) DNA (types 6, 11, 16, 18) was not pr