"After careful and deliberate consideration, I've decided to resign today," said a smiling Cowher, "And I've given it a lot of thought and I believe it is in the best interests of our family and myself at this time."
Cowher, 49, who grew up in Crafton, Pa., just outside Pittsburgh, said he had been fortunate to coach the team he grew up watching and to stay close to family.
Cowher took the Steelers job in 1992 succeeding Chuck Noll and led Pittsburgh to a 149-90-1 regular-season record with just three losing seasons. The Steelers were 12-9 in the post-season, including two Super Bowl appearances.
The team finished 8-8 this season after posting a 15-1 regular-season record in 2004 and an 11-5 record in 2005 and a Super Bowl XL championship.
"We would like to thank Bill Cowher for his tremendous contributions to the Steelers organization and for leading us to our fifth Super Bowl title," said Steelers President Art Rooney II. "Bill will always be a valued part of Steelers history and tradition, and we wish him the very best with all future endeavors."