The pope's surgeon, Dr Stefano Margaritora, head of thoracic surgery at Gemelli Hospital, accompanied him to the hospital door. Leo waved to the crowd and briefly stopped when a teenage girl presented him with a homemade papal doll.
Doctors cleared the pope to return home after completing the latest blood tests and chest imaging, according to reports. The operation on Tuesday removed the lower lobe of his right lung.
Leo will hold his first public engagement since the surgery on Sunday (Rome time), when he leads weekly prayers with pilgrims in St. Peter's Square at midday.
Pope Leo has been diagnosed with lung adenocarcinoma, the most common form of lung cancer. The diagnosis for a pope elected only in May 2025 and known for his relatively young age and energetic style caused shock and raised questions about the future shape of his papacy as he deals with the illness.
Doctors have said the surgery was completed successfully without complications. They have not yet disclosed the size of the tumour or whether the disease had spread to nearby lymph nodes, both key factors in determining prognosis.