To shake the opponents' hands after games will be compulsory for every player.
The decision, which takes effect in January, came in response to public approval after Fiorentina did just that Sunday after a 2-0 loss to Inter Milan. Fiorentina lined up near the tunnel leading to the locker room and shook the Inter players' hands as they left the field.
The gesture by the Tuscan squad came after a good-tempered match - the first game for Fiorentina since the death of coach Cesare Prandelli's wife.
"It's something that should be extended to the entire world of soccer," AS Roma captain Francesco Totti said. "Being sporting enemies on the field but then greeting (opponents) as friends after the final whistle."
Already nicknamed the "third half," the league will decide on details of the procedure for both Serie A and B at its next meeting on Dec. 13. Handshakes after games have long been a ritual in rugby and ice hockey.
Last month, a Lazio fan was killed by a policeman at a highway rest stop in Tuscany, sparking riots in stadiums and cities across the country.
"This is another gesture to ease tempers and most of all to provide a positive image of what happens on the field and transport it to the stands," AC Milan coach Carlo Ancelotti said.