Lung cancer is the second most commonly diagnosed cancer in both males and females and the leading cause of cancer-related death in the United States. Lung cancer affects some races more than others; blacks have higher incidence and mortality rates than do whites. This report presents the first analysis of lung cancer incidence among racial/ethnic groups by U.S. census region. CDC analyzed data collected by CDC's National Program of Cancer Registries (NPCR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program for the period 1998-2006. These combined data reflect new lung cancer cases representing approximately 80% of the U.S. population. During this study period, annual incidence per 100,000 population was highest among blacks (76.1), followed by whites (69.7), American Indians/Alaska Natives (AI/ANs) (48.4), and Asian/Pacific Islanders (A/PIs) (38.4). Hispanics had lower lung cancer incidence (37.3) than non-Hispanics (71.9). Incidence varied greatly with age, peaking among persons aged 70-79 years (426.7). The region with the highest incidence was the South (76.0); the lowest was the West (58.8). Among whites, the highest lung cancer incidence was in the South (76.3); the highest incidence among blacks (88.9), AI/ANs (64.2), and Hispanics (40.6) were in the Midwest, and the highest incidence among A/PIs was in the West (42.5). These findings identify the racial/ethnic populations and geographic regions that would most benefit from enhanced efforts in primary prevention, specifically by reducing tobacco use and exposure to environmental carcinogens.