The 2012 Kakkonen season began on 18 April and ended on 6 October 2012.
[1] A total of 40 teams contested the league divided into four groups, Eteläinen (Southern), Pohjoinen (Northern), Läntinen (Western) and Itäinen (Eastern).
30 returned from the 2011 season, three relegated from Ykkönen and seven promoted from Kolmonen.
The bottom two teams in each group and the worst eight-placed qualified directly for relegation to Kolmonen.
[5] Group winners Eteläinen (Southern): ÅIFK Pohjoinen (Northern): AC Kajaani Läntinen (Western): Ilves Itäinen (Eastern): JäPS AC Kajaani won 1–0 on aggregate.