Two cases of mucinous cystadenocarcinoma of the pancreas are described in which the diagnosis was made from the material obtained by a computed tomography-guided fine-needle aspiration cytology examination. It is strongly felt that aspiration cytology, when performed under imaging guidance, is sensitive and specific in the diagnosis of mucinous cystadenocarcinoma and allows for a relatively simple yet confident diagnostic interpretation of this uncommon pancreatic tumour.