The three-time FIFA World Cup winner required an operation to remove a colon tumour in September and has since continued undergoing chemotherapy as part of the rehabilitation process.
Sao Paulo's Hospital Albert Einstein confirmed on Thursday (AEDT) that Pele had been hospitalised again, adding he is in stable condition and should be discharged in the next few days.
"The patient is stable, and the forecast is that he will be released in the coming days," the statement said.
The legendary striker has suffered from ill health in recent years, having prostate surgery in 2015 after being admitted to hospital twice in six months, and he was hospitalised again for a urinary infection in 2019.
Pele is the only player to hold three World Cup winner's medals, lifting the trophy in 1958, 1962 and 1970.
The 81-year-old is also one of just four players to score in four different World Cups, while he remains Brazil's all-time leading goalscorer - having found the back of the net 77 times in 92 appearances for the Selecao.