كتب : Omar AbdelAziz
"We would like to thank Khalid for his contribution while he was with Chelsea FC and would like to wish him luck at his new club," a Chelsea statement read.
Stuttgart were admittedly interested in the 26-year-old full-back, who played for Hamburg before joining the Blues two years ago.
"He is just the man we were lacking. He is one who is not scared of getting involved when needed," Stuttgart coach Armin Veh told German daily Bild.
Boulahrouz failed to impress in his first season at Stamford Bridge and was loaned out to Sevilla last season, but also found life difficult.
However, the versatile defender shone for Holland in EURO 2008, despite getting a unexpected call-up by the Oranje.