Occupational causes of cancer are difficult to establish because of the long latency period and difficulty in identifying occupational linkages. This study provides a regional analysis of cancer incidence and mortality as a method of identifying localizing factors in cancer that can be followed by more specific epidemiologic investigation. In this study we analyze the regional standardized mortality ratios (SMRs) for site-specific cancers, by age, sex and continent of birth for the years 1983-86, for the Jewish population of Israel. Elevated total malignant and benign neoplasm SMRs were found in Acre (SMR 109, P < 0.05), Haifa (104, P < 0.05) and Tel Aviv (107, P < 0.001). The only other statistically significantly elevated SMRs were found in Acre for lung cancer (133, P < 0.05) and leukemia (171, P < 0.05). Age and sex-standardized incidence ratios (SIRs) by regions are also presented for the years 1980-81 for the Jewish population. Haifa had elevated SIRs for colorectal cancer (126, P < 0.001), breast cancer (118, P < 0.01) and lymphomas (126, P < 0.05). Elevated lung cancer SIRs were found in both Acre (145, P < 0.05) and Ramla (143, P < 0.05). Male to female incidence ratios (MFIRs) for ages 30+ for the Israeli Jewish population are also presented. Elevated bladder cancer MFIRs were found in the heavily industrialized Haifa region (7.69 vs. 4.62 P < 0.05). For Ramla residents, bladder and oronasopharyngeal cancer MFIRs were approximately three times the national average (not statistically significant). Ramla also had elevated MFIRs for lung cancer (14.9 vs. 3.4 nationally, P < 0.01), as did Acre (7.6 vs. 3.4 nationally, P = 0.06). These elevated MFIRs are suggestive of occupational exposure from the cement and asbestos factories in the Ramla and Acre regions. Regional analyses of cancer mortality and cancer incidence (using SMRs, SIRs and MFIRs) can serve as a basic tool for identifying sentinel markers of excess rates. Our findings indicate regions where we should undertake case-referent studies in order to identify potential risk factors and where to target possible preventive programs.