This book is focused on the basics of applying thermochronology to geological and tectonic problems, with the emphasis on fission-track thermochronology. It is conceived for relatively new practitioners to thermochronology, as well as scientists experienced in the various methods. The book is structured in two parts. Part I is devoted to the fundamentals of the fission-track method, to its integration with other geochronologic methods, and to the basic principles of statistics for fission-track dating and sedimentology applied to detrital thermochronology. Part I also includes the historical development of the technique and thoughts on future directions. Part II is devoted to the geological interpretation of the thermochronologic record. The thermal frame of reference and the different approaches for the interpretation of fission-track data within a geological framework of both basement and detrital studies are discussed in detail. Separate chapters demonstrate the application of fission-track thermochronology from various perspectives (e.g., tectonics, petrology, stratigraphy, hydrocarbon exploration, geomorphology), with other chapters on the application to basement rocks in orogens, passive continental margins and cratonic interiors, as well as various applications of detrital thermochronology.