Excited children threw baseball caps, kerchiefs and even a paper plane at the 77-year-old Argentine pontiff as he toured the Vatican piazza and the avenue leading to St Peter's Basilica on his white "popemobile".
"This is not a lament, it's a celebration for education! We know there are problems and things that don't work but you are here, we are here because we love school," the pontiff told the crowd.
Francis also shared a memory about his first teacher, adding: "We love school because it is synonymous with openness to reality, or at least it should be".
The event was organised by the Italian Bishops' Conference whose leader Cardinal Angelo Bagnasco pointed to "problems" and "difficulties" in Italy's education sector and said: "Sometimes it's a struggle to rekindle the hope of being able to teach".
Italian Prime Minister Matteo Renzi has promised to invest more in education after successive austerity budget cuts that have hit schools in recent years.