The hugely popular and world-famous Ethiopian will still participate in races but no longer with the intention of getting on the podium.
It brings to an end a phenomenally successful career which stretched back more than two decades in which he claimed two Olympic gold medals over 10,000m, in 1996 and 2000, nine IAAF world titles, including four consecutive IAAF World Championships 10,000m wins, and he set 15 official world records outdoors as well as five world indoor records.
He first came to international attention when he won the 5000m and 10,000m double at the 1992 IAAF World Junior Championships.
His road running career saw him become the first runner to go under 2:04 for the marathon when he ran 2:03:59 in Berlin in 2008.
Although some of his records have since been surpassed, notably on the track by his compatriot Kenenisa Bekele, Gebrselassie remains the world record holder at 20,000m and one hour.
Read more at: IAAF.org