Abstract: The geographic distribution of breast cancer in Texas counties from 1980 to 1998 was examined using data from the U.S. Census Bureau and the Texas Vital Statistics. The effects of race/ethnicity, socioeconomic status, genes and environment on cancer morbidity and mortality was examined using ArcGIS and statistical analysis of secondary data in a human ecology framework. In the study age-adjusted mortality rates in Texas counties were found to be positively correlated with percentage of the population of the county that was Black (r = .123, p < .05), the percentage of the county population that was White (r = .172, p < .05), the percentage of the county population uninsured (r = .103, p < .05), and the population density of the county (r = .136, p < .05). Age-adjusted mortality rates were inversely correlated with percentage of the county population that was Hispanic (r = -.166, p < .05), the percentage of the county population that was employed (r = -.203, p < .05), the average income of the population of the county (r = -.281, p < .05), and the average years of education of the population (r = -.249, p < .05).