Life prediction methods are required to assess the performance and safety of the structural materials used in engineering systems and components that operate at high temperatures. At high temperatures, materials are subject to time-dependent creep environmental degradation, as well as cycle-dependent fatigue degradation. The life prediction methods must account for all of these degradation mechanisms and their possible interactions. The purpose of this paper is to review the methods that are used predict the creep and fatigue life of structural materials. Traditional methods that have been used to predict the life of structural materials are based on the initiation of a significant crack; whereas more recent methods employ fracture mechanics to predict life based on the growth of crack from some initial size to a critical size. Crack-growth-based life prediction methods are emphasized in this review.