We conducted a preliminary survey on 3064 patients who underwent upper gastrointestinal endoscopy at the Al-Thawra Hospital in Sana'a, Republic of Yemen, between January and December 1991. The age/sex distribution, demographic features and social habits with respect to cigarette and water-pipe smoking and Qat chewing were compared for patients with oesophageal and gastric cancers (n = 183). A preponderance of women with carcinoma of the mid-oesophageal was noted, previously only recorded in areas of high prevalence. Unlike Western populations, smoking and alcohol consumption were not significant risk factors. A high frequency of Qat chewing and water-pipe smoking was found for both men and women and for a group with tumours of the gastro-oesophageal junction or cardia (chi 2 = 2.646, P > 0.05). Numbers were insufficient to identify independent effects of each factor individually. Dietary habits alone were insufficient to account for the excess of affected females. A case-control study is now underway to investigate further the role of dietary factors, social habits, demographic features and Helicobacter pylori infection on the development of upper gastrointestinal cancer in the Yemen.