The primary objective of the Iowa Centenarian Study is to further our understanding of determinants of exceptional longevity above and beyond health outcomes, particularly in rural environments. This introductory article provides a general overview of the study, its methodology and basic descriptive results. One hundred and fifty-two centenarians from a rural state participated in the study (average age was 101.6 years). Baseline data collection included questions on demographics, cognitive representation of being a centenarian, mental status, past family history, life events, activities of daily living, coping, physical health and health history, nutrition, exercise, personality, social support, mental health, economic status and perceptions, and fatigue. A subset of the baseline sample (n = 28) participated in a short-term longitudinal study that assessed stability and change in mental status, mental health, and activity. Four additional papers in this issue (Franke, Margrett, Heinz, & Martin, 2012; Garasky, Martin, Margrett, & Cho, 2012; Margrett, Hsieh, Heinz, & Martin, 2012; Martin, da Rosa, Margrett, Garasky, & Franke, 2012) will highlight substantive findings, including longitudinal analyses, in activities of daily living, economic status, mental status, and positive and negative affect. (Contains 2 tables and 3 figures.)