The former Archbishop of Cape Town was readmitted to a South African hospital as a precaution after a surgical wound displayed "signs of infection".
The 84 year old, who was an outspoken critic of apartheid in South Africa and was awarded the Nobel Peace Prize in 1984, left hospital just days ago after receiving three weeks of treatment.
Tutu had surgery ten days ago to tackle "recurring infections resulting from past treatment received for prostate cancer", a disease he has been treated for over many years.
Last year, he was hospitalised on several occasions.
Among those taking to social media to offer messages of support, Stefan Simanowitz from Amnesty International, wrote on his own personal Twitter account: "Get well soon Arch".