Oral use of smokeless tobacco has been associated with the development of oral cancer. Shamma is a preparation of smokeless tobacco. Previous investigators in the Kingdom of Saudi Arabia (KSA) have reported a relationship between their patients with oral cancer and a history of using shamma. The purpose of this study was to explore the possible relationship between a smokeless tobacco preparation (shamma) and oral cancer, among the provinces of the KSA. Tumor Registry (TR) data from the King Faisal Specialist Hospital and Research Centre (KFSH&RC) were reviewed for the period from 1976 to 1995. A total of 26510 Saudi cancer patients were referred over this 20-year period. The frequency of oral cancer was investigated, specifically for those primary sites located near the habitual placement of this smokeless tobacco product. Notably, 35.4% of these oral cancers were referred from one province - Jizan. The percentage of oral cancer cases from this province is significantly higher than the percentage of total malignant cases referred to KFSH&RC from this province, and the Saudi population of this province when compared to the whole of the KSA. These data suggest that there is a relationship between the factors smokeless tobacco product (shamma), frequency of oral cancer, and Jizan province: oral cancer appears to be more common in this province where shamma is also common.