Dear Editors, suspected superficial mycosis of the skin is usually detected directly by microscopy (KOH mounts) and by culture of lesional scales. 1 Occasionally, however, an unexpected fungus is discovered only after histological examination of a skin biopsy taken for another suspected diagnosis by using periodic acid-Schiff (PAS) staining. Furthermore, nail material is often sent straight away for histological examination with PAS staining with the question "onychomycosis?".Although fungi are detected in formalin-fixed skin and nail preparations by PAS staining, species identification is not possible by histomorphology. Since accurate pathogen identification is important for treatment and as PCR analysis does not require vital fungal elements, we wanted to investigate in a pilot study whether dermatophytes can be identified "retrospectively" at the species level in formalin-fixed, paraffin-embedded skin and nail specimens by PCR.There is little information in the literature on laboratory methods for skin sample analysis, and a standardized procedure is lacking. 2 In addition, such a procedure is still considered of secondary importance for dermatomycoses. 1 Recently, Trichophyton (T.) verrucosum was successfully detected by PCR after DNA extraction from a formalin-fixed skin biopsy. 3 We have therefore processed archived formalin-fixed skin biopsies with PAS-positive fungal elements as well as formalin-fixed nail material (PAS-positive and PAS-negative) at our clinic for subsequent mycological PCR diagnostics using a commercial assay.