The authors describe a case of cutaneous neuroendocrine (Merkell cell) carcinoma in a patient previously treated for Chronic Lymphocytic Leukaemia (CLL). The authors discuss some of the mechanisms concerning the increased frequency of a second tumour in patients with CLL and focus attention on the high incidence in CLL of secondary tumours, especially skin tumours, of which Merkell cell carcinoma is a rare example. The authors consider the possible therapeutic approaches, reported in the literature, for the treatment of this particular skin carcinoma, which on account of its aggressiveness and the preexistence of a leukaemic process requires a particularly careful therapeutic approach.