Martins has previously worked at Sporting Lisbon, where he oversaw the Under-17 and Under-19 sides and was also the club's assistant coach in 2004-05, and Braga. Last year he travelled to Saudi Arabia to work with the national and Olympic teams.
A short statement on Tottenham's official website said: "The club is delighted to announce the appointment of Luis Martins as first-team coach."
Martins will work beneath new Tottenham boss Andre Villas-Boas, who has yet to recruit his number two.
Source: PA
Source: PA