A case of mucinous (adenocystic) carcinoma of the skin (MC) is presented. The differential diagnosis against metastasis from mucinous adenocarcinoma (mammary gland, gastrointestinal tract, ordinary sweat gland carcinoma) is emphasized. MC is characterised by its abundant content of non-sulphated mucopolysaccarides. MC is low-malignant with a tendency of local recurrence. Excision and subsequent yearly control is the treatment of choice.