Jenkins made his debut for Wales in 1991 against France and went on to make 58 caps for his country.
He started his career at Ynysybwl before moving to New Zealand where he played for Taupo and King Country.
Jenkins then returned to Wales to play for Pontypridd and Pontypool before moving to Swansea in 1991.
He played in three World Cups during his time with the national team.
Jenkins, 36 made his decision after consultation with the medical profession confirmed that it would be sensible to retire rather than risk further injury.
Garin Jenkins told the Western Mail: “I’ve had previous neck injuries and been able to recover but this time the symptoms are worse and the weaknesses greater.
“Malcolm Downes, a surgeon who has helped me recover from past problems, has advised me against me playing rugby until a further examination by a spinal expert and there is a likelihood of surgery to remove a disc in my neck.
“That means the end of my career. But I can look back on some very fond memories – I’ve thoroughly enjoyed my career.”