Hall, 32, informed Cricket South Africa (CSA) in writing on Friday that he would sever all ties with the Proteas. His contract with CSA had recently been upgraded and was due to end in April 2008.
Hall, a veteran of 21 Tests and 88 ODIs, was left out of the final 15-man squad for the inaugural Twenty20 World Championships in South Africa later this month.
While the omission of Jacques Kallis made headlines, the snubbing of Hall, who had been the best South African bowler on display during the World Cup was in itself a shock.
"It took me completely by surprise," Tony Irish, the South African Cricketers' Association chief executive, told the Pretoria News on Friday.
"Usually, I'm aware of what a player's thinking and they consult me. But this came out of the blue.
"I was told today by CSA about the resignation and immediately contacted Andrew.
"He made it clear to me that his decision was not open to debate. I told him that I was concerned about the way he had handled the matter and said I was disappointed with his attitude."
Graham Ford, the coach of Kent, commented on Hall's improvement with the ball during his stint with the county this summer and shed some light on the South African's decision to quit.
"He felt he had done a lot to cement his place in the national team and had received an improved contract from CSA," said Ford.
"I can only assume that he was reacting to the bitter disappointment of being left out of the (Twenty20) World Cup squad."
Hall has also asked to be released from his domestic contract with the KwaZulu-Natal Dolphins. He has abandoned his plans to live in Durban and has moved back to Gauteng.
Is Andrew Hall's international retirement a symptom of a larger malaise in South African cricket?