Benedict thanked the staff of the Gemelli Polyclinic hospital during a visit to the Sacred Heart Catholic University, of which the hospital is a part. He was invited to inaugurate the university's academic year, as John Paul did in the past.
During his 26-year pontificate, John Paul was treated at the Gemelli several times, including twice in February after suffering breathing problems related to the flu. He died in his Vatican apartment April 2.
During his stay at the Gemelli, John Paul appeared at the window of his 10th floor suite to bless the crowds who held vigil for him, once unable to speak because he had a breathing tube.
"Finding ourselves here together, my dear friends, we can't but think of the anxiety- and emotion-filled moments that we lived during the last hospitalizations of John Paul II in this Policlinic," Benedict said.
"In those days, the thoughts of Catholics and others from around the world were turned toward the Gemelli," he told members of the university's medical school staff.
"From his hospital room, the pope taught everyone an incomparable lesson of the Christian sense of life and suffering, witnessing in first person the true Christian message," he said.
He thanked the staff for their care in treating John Paul, and said they would find their "heavenly rewards."
It was the second time Benedict had returned to the grounds of the Gemelli since John Paul's death. On Aug. 5, Benedict visited his brother Georg, who had been staying with the pope at his summer residence but was taken to the Gemelli and outfitted with a pacemaker because of an irregular heartbeat.
During his speech, Benedict praised the work of the Catholic university, calling it a "great laboratory" where the dialogue between faith and reason meet.
He cited in particular the university's institute on human infertility, inaugurated during John Paul's pontificate, and said its promotion of "responsible procreation" was also close to his heart.
"This is the great challenge of Catholic universities: doing science on the horizon of a rationality that is different from the dominant one today, according to a reason that is open to transcendency, to God," he said.
Benedict has not made many official outings in Rome, but of the few he has made two have been to Catholic hospitals: In addition to Friday's visit, he spent a morning at Rome's main children's hospital on Sept. 30, meeting with sick children and their parents.