We retrospectively studied 8 cases of adenocarcinoma of the vermiform appendix diagnosed in Iceland 1974-1990. There were five males and three females. The age ranged from 25¬83 years, mean age 55.8 years. Five had mucinous adenocarcinoma, two had adenocarcinoma and one had adenosquamous carcinoma. Two patients had a villous adenoma in association with the tumour. Three tumours were located distally and three proximally in the appendix, in two cases the location of the tumours was unknown. In four patients the clinical presentation was that of acute appendicites with duration of symptoms ranging from 1-10 days. All of these patients underwent a primary appendectomy. Two patients later underwent right hemicolectomy, one patient underwent ileocaecal resection and one patient underwent an explorative laparotomy with mesenteric lymph node biopsy. Three of these patients were alive at the end of 1990, 16 years, 3 years and 16 months after diagnosis. One patient died of disease 7 years after diagnosis. In four the mode of presentation was that of metastatic disease of unknown origin. In one of these patients the diagnosis was made after appendectomy for ruptured appendicitis. In the other three the diagnosis was made at autopsy. Two had pseudomyxoma peritonei. One of these patients received chemotherapy and later underwent removal of tumour bulk. Another patient received radiation therapy and chemotherapy. Survival for these four patients was less than one year. No tumours were diagnosed in en passant removed appendices. The incidence of adenocarcinoma of the vermiform appendix in Iceland during the period 1974-1990 is approximatley 0.2 cases /100.000 /year.