Lega Pro Prima Divisione was the name of the third highest football league in Italy. It consisted of 33 teams, divided geographically into two divisions of 16 and 17 teams for group A and B respectively. Until 2008 it was known as Serie C1.
Before the 1978-79 season there were only three leagues of professional football in Italy, the third being Serie C. In 1978, it was decided to split Serie C into Serie C1 and Serie C2. Serie C2, the fourth highest professional league in the Italian system, was also renamed in 2008 and was called Lega Pro Seconda Divisione. The reform, already decided by the FIGC led to the reunification with the second division starting from 2014-2015 and with the subsequent rebirth of the third division championship organized by the pro league with 60 teams divided into three groups of 20.
In each division, two teams were promoted to Serie B, and three teams were relegated to Lega Pro Seconda Divisione. In total, the league promoted 4 teams to Serie B and relegated 6 teams to Seconda Divisione.
The team finishing first in the regular season was directly promoted to Serie B, while teams placing 2nd to 5th were entered into a play-off semi-final for the chance of gaining the second promotional spot for that particular division.
In the play-off phase after the regular season was completed, in each division the team placed 2nd had played the team placed 5th, and the team placed 3rd had played the team placed 4th in a two-legged semi-final series with the higher classified team having home advantage in the second leg. In case of an aggregate tie score, the higher classified team was declared the winner without extra time or penalty kicks. The winning teams advanced to the final in another two-leg tie with similar rules. The only difference being that if an aggregate tie existed at the end of the second match, extra time was played. If the tie persisted, again the higher classified team was declared the winner and no penalty kicks were taken. The winner became the second team promoted for that particular division to Serie B.
The team finishing last in the regular season was directly relegated to Seconda Divisione, while teams placing 14th to 17th are entered into a relegation playoff phase called play-out. There was only one round in the play-outs. In each division the team placed 14th had played the team placed 17th, and the team placed 15th had played the team placed 16th in a double-leg series with the higher classified team having home field advantage in the second leg. In case of an aggregate tie score, the rules were exactly the same as those for the promotional semi-finals. The two winning teams remained in Prima Divisione while the two losing teams became the second and third teams relegated for that particular division.