The Spaniard has been in the backroom staff in the Spanish capital since 2013 coaching the youth sides but has been actively seeking new employment this summer, even reportedly applying to become the new manager of Scottish Premier League club St Mirren.
However, he has confirmed that his next step will take him to Turkey.
“Today, I want to thank Real Madrid, my home for all the years that I enjoyed as a footballer and a coach,” he confirmed via Instagram.
“In a few days, I will make Besiktas my new home, where I will be an assistant coach and where I can continue to grow professionally.
“I’m grateful to Besiktas for the love and trust that you have placed in me. I will return it to you with a lot of work and enthusiasm.
“My family and I are looking forward to this adventure in Istanbul. Let’s go for it!
“Always Black Eagles.”
Guti, 41, enjoyed a storied playing career that saw him spend 24 years with Real as a youth and senior player, claiming five league titles and three Champions Leagues while at the club.
Indeed, the only spell he has spent away from the Bernabeu as a professional was a one-year stint at Besiktas at the end of his career, where he helped the club to the Turkish Cup of 2010-11.