Identification of fungal pathogens in clinical samples by hybridization with short oligonucleotide probes is increasingly used in the diagnosis of invasive fungal infections. Rapid and specific fungal identification has been documented in different diagnostic settings allowing for specific patient management. Identification of fungal pathogens in formalin-fixed, paraffin-embedded tissue samples appears to be rewarding as these materials are stored in pathology archives offering an insight into the etiology of deep fungal infections that is often not achieved by non-molecular tests. In contrast to PCR based methods, amplification of target sequences is unnecessary limiting the potential for contamination and localization within infected tissue is possible helping to distinguish between colonization and infection.