Post mortem examination of a juvenile loggerhead sea turtle (Caretta caretta) stranded in the Canary Islands revealed a fishing-line in the small intestine. Histologically, severe necrotic enteritis, multiple haemorrhages, and marked oedema of the intestinal submucosa were observed. Yeast cells and fungal hyphae were seen in the lamina propria of the intestinal mucosa and in the connective tissue of the submucosa. Because fungal cultures were not taken at the time of necropsy, an immunohistochemical study was performed in order to identify the fungus involved. Specific monoclonal and heterologously absorbed polyclonal antibodies served as the primary reagents for identification of aspergillosis, candidiasis, fusariosis, geotricosis, scedosporiosis, and zygomycosis, using an indirect immunofluorescence staining technique. The fungal elements were strongly stained only by a polyclonal antibody against Candida albicans and a monoclonal antibody against C. albicans. There are no known previous reports of Candida sp. causing skin disease or systemic mycotic infection in sea turtles.