Graeme Smith will not return to Surrey next season to fulfil the final year of his contract.
The former South Africa captain signed a three-year deal with the county in 2013 but played just three first-class games in his first season before fracturing his knee at the start of this term.
That injury ruled Smith out for the rest of 2014, and now doctors have advised him he will not be able to "fulfil the
day-to-day duties of a full county season".
"I thoroughly enjoyed the privilege of captaining Surrey but due to my injuries in 2013 and 2014 I have been unable to fulfil my role in achieving the goals that both Surrey and I set out to accomplish when I first arrived," he said.
"I would like to thank Surrey for the way they have looked after me. They have made me feel very welcome and it is very apparent that the current cricket management and personnel in the dressing room are already well on their way to achieving these goals.
"I will continue to follow the club's progress over the coming years."
Surrey director of cricket Alec Stewart said: "On behalf of the club, and particularly the dressing room, I would like to thank Graeme for the impact he has had in the time that he was with us over the last two years.
"As a person and leader his qualities have helped lay the foundations for the progress that we all want for the club.
"We wish Graeme the very best in the next stage of his career and he will always be welcomed at the Kia Oval."