One of the most remarkable life history traits of many species of eusocial insects is the extraordinary longevity of their queens, with the recorded life span of some individuals exceeding 30 years. Surprisingly, little research has been conducted on either the proximate or ultimate questions concerning what factors favor the evolution of the long life spans in social insects. The broad objective of this paper is to address four sets of questions: (1) What are the similarities and differences in the longevity patterns among species in the four main groups of social insects - bees, wasps, ants and termites? (2) What is the evolutionary association of longevity and sociality in insects? (3) Are there biodemographic principles that can be derived from studies on longevity in social insects? and (4) What are the general implications for longevity in vertebrates, including humans?