In this chapter, most of the mesenchymal (soft‐tissue) tumours involving the skin (including subcutaneous tissue) are described. Practically any soft‐tissue tumour can involve or originate from the skin including the subcutaneous tissue. Although most soft‐tissue tumours arising in the skin are benign or low‐grade malignant (e.g. dermatofibrosarcoma protuberans), some malignant tumours may primarily originate in the skin and their behaviour is usually aggressive. Examples of the latter include angiosarcoma and epithelioid sarcoma. Cutaneous soft‐tissue tumours are often difficult to diagnose histologically and benign lesions are often erroneously diagnosed by pathologists as malignant leading to unnecessary treatment.