"Tony Pulis has agreed a further one-year extension to his contract which commits him to The Hawthorns until the summer of 2018," a club statement said on Friday.
The Welsh coach came to West Brom in January 2015 and in two seasons he has led the team to a comfortable place where it stays under the spotlight, finishing the English Premier League (EPL) in 13th and 14th position.
The club was sold last September to a Chinese investor group led by businessman Guochuan Lai, who has shown his confidence in Pulis by offering him a new contract, reports Efe.
"This is a time of great change at Albion and when that happens you need continuity," Pulis said in a statement to the website of the 'Baggies'.
"I want to build things here and play my part in improving the Club. You cannot do these things overnight but I do believe, step by step, we are making advances," added the coach.