The 80-year-old had surgery to remove a tumour from his colon earlier this month and was released from intensive care on Wednesday.
Sao Paulo's Albert Einstein Hospital confirmed he was readmitted "as a preventative measure".
"He is recovering well and within normal range," Kely Nascimento said.
He had been having treatment at the hospital since 31 August after the tumour was detected in routine tests.
Media outlets in Brazil had earlier reported Pele was readmitted to intensive care as a precautionary measure because of his age.