Primary mucinous carcinoma of the skin (PKMK) is a rare malignant tumour of the sweat glands. It is often misdiagnosed as it has an uncharacteristic gross appearance - and may microscopically resemble a cutaneous metastasis from a mucinous carcinoma of the breast, gastrointestinal tract, lungs, ovaries or prostate. The recurrence rate is high, but mortality is low. A MEDLINE literature search was performed for reports on PKMK. A total of 228 cases were identified. These are presented with regard to tumour characteristics and clinical features as well as histopathological and immunohistochemical findings.