In an adult female of the common eel Anguilla anguilla a large lipoma was found, situated on the left side, caudally of the left operculum. Microscopically, the tumour, which originated from the subcutaneous connective tissue, was composed of areas of adipose tissue and areas of fibrous connective tissue. The tumour belongs to the fibrolipomatous type and shows a striking resemblance with the lipoma, described by Stolk (in press) in the lizard Lacerta muralis.