He was due to attend a virtual court hearing on Thursday in a dragging graft case relating to an arms purchase in 1999 when he was deputy president.
But the National Prosecuting Authority (NPA) on Tuesday said the upcoming hearing would serve to postpone the trial to September 20 and 21.
The delay is meant to “enable the state-appointed medical team of specialists to consider evidence in cooperation with Mr Zuma’s medical team”, it said in a statement.
Details of Zuma’s medical condition have been kept confidential. He was hospitalised from jail in early August and underwent surgery later that month.
Critics accuse the ex-president and his legal team of using delaying tactics to escape justice.
The main opposition Democratic Alliance party has accused the prison services of bias, and vowed “legal steps” to review the decision process behind the parole.
Zuma faces 16 counts of fraud, graft and racketeering related to the 1999 purchase of fighter jets, patrol boats and equipment from five European arms firms.
He is accused of taking bribes from one of the firms, French defence giant Thales, which has been charged with corruption and money laundering.
Both deny wrongdoing.
Court proceedings have been repeatedly delayed for more than a decade as Zuma’s lawyers have fought to have the charges dropped.
The trial was last postponed to September 9 pending a medical report on Zuma’s fitness.