Construction began on Monday and was expected to be completed in the first quarter of 2016, it said in a statement.
“We are confident that Group Five will be the right partner as we navigate what is for the hospital trust, unchartered territory,” trust chairman Moss Ngoasheng said.
The appointment of Group Five followed submissions by various contractors and an adjudication process.
“This represents a key milestone in our efforts to make [former president] Nelson Mandela’s last wish of building a children’s hospital in South Africa a reality,” trust deputy chair Nana Magomola said in the statement.
She said there was still a long way to go.
“But we are confident that with the support of those who share this dream, we will be able to build and present to the public a fitting last legacy of this international icon.”
The hospital was expected to employ around 150 doctors and 451 paediatric nursing professionals.
The Nelson Mandela Children’s Hospital Trust was presently raising funds to get R1 billion to build and equip the hospital, and train medical professionals.
“The Nelson Mandela Children’s Hospital will be a world class, highly advanced specialised children’s hospital that will shape the lives of the children of Africa and shape the future of a greater Africa,” the trust said.
“It will work on a referral basis across all its centres of excellence. The hospital will be located adjacent to Wits University’s medical school in Parktown.”