Gammons has been an ESPN reporter and analyst for 20 years and started his reporting career for the Boston Globe in 1969.
"My decision to leave ESPN and move on at this point in my life has been conflicted," Gammons said in a statement on the network's Web site. "I owe a great deal of my professional life to ESPN, having spent more than half of my 40 years in journalism working for the network, and the choice to move on was made with nothing but the strongest feelings for the people with whom I worked. ESPN gave me a great deal more than I gave it, and will always be a huge part of who I am.
After being elected to the Baseball Hall of Fame in 2005, Gammons suffered a brain aneurysm the following year, but returned to the air.
An accomplished musician, Gammons released a CD in 2006 entitled "Never Slow Down, Never Grow Old."