Technical intelligence (TECHINT) is intelligence about weapons and equipment used by the armed forces of foreign nations. The related term, scientific and technical intelligence, addresses information collected or analyzed about the broad range of foreign science, technology, and weapon systems.

Technical intelligence is intended primarily to counter technological surprise. Knowledge of the characteristics and capabilities of enemy weapons allows nations to develop effective countermeasures for them. Occasionally, armed forces adopt technology developed by foreign nations. The jerrycan of World War II is an example of foreign equipment adopted by the US Army. Technical intelligence should not be confused with intelligence obtained "by technical means". That is a term of art used in discussion of disarmament to mean information gathered by various sorts of cameras, sensors, or other devices. Technical intelligence is the product: "technical intelligence—Intelligence derived from the collection, processing, analysis, and exploitation of data and information pertaining to foreign equipment and materiel for the purposes of preventing technological surprise, assessing foreign scientific and technical capabilities, and developing countermeasures designed to neutralize an adversary's technological advantages."

Scientific and technical intelligence (S&TI) is "the (All-source intelligence) analysis and production resulting from the collection, evaluation, analysis, and interpretation of foreign scientific and technical information that covers:

S&TI covers not just the equipment, but the process by which it was developed and produced, the production rate of the country or organization making it, and possibly the economic and other priorities given to the project.

The production of technical intelligence is a specialized intelligence art used to meet the needs of the armed forces and national intelligence consumers. A multiservice manual describes U.S. military doctrine for TECHINT. The technical intelligence process is divided into three areas—collection, exploitation and production.

Chance plays an important part in the collection of foreign weapons and equipment. The collection phase typically begins when a soldier finds something interesting on a battlefield or a defecting pilot flies an aircraft to a friendly country. In a famous case, Viktor Ivanovich Belenko flew a Soviet Mig 25 "Foxbat" to Hakodate, Japan on 6 September 1976. The United States granted Belenko asylum and assisted in the dismantling of the aircraft so that it could be crated for return to the Soviet Union.

Procedures have been established for development of scientific and technical intelligence requirements, i.e. wish lists, to guide systematic collection efforts. Materiel required may be obtained through any number of channels. For example, materiel may be obtained through commercial channels.^{[citation needed]}

An attache might ask a foreign official for information about a piece of foreign equipment. Clandestine operations have been mounted to obtain critical enemy materiel. Probably the most expensive and most ambitious was the construction of Hughes Glomar Explorer by the Central Intelligence Agency to obtain the wreckage of Soviet submarine that sunk in the Pacific.^{[citation needed]}