The clubs have battled for League Two titles, League One promotions and simply for local bragging rights.
There have been memorable play-off games (for Posh at least) and high drama with both teams recording victories after being reduced to nine men.
Players and managers who have gone on to better things have been involved in the matches
The teams have met 27 times in all competitions with Posh leading the head-to-head 12-10 with five draws.
Here is a selection of dramatic highlights from Posh v MK.
1.
December 2007: Posh 1, MK Dons 2: The teams were battling away at the top of League Two when MK arrived at London Road to pinch a vital win through goals from Kevin Gallen and Keith Andrews. Aaron Mclean's Posh reply arrived too late to affect the final result. Rival managers Darren Ferguson (left) and Paul Ince are pictured. Photo: PA
2.
March 2008: MK Dons 1, Posh 1: The battle for the League Two title was still raging when the return game was played at stadium:mk. Aaron Wilbraham fired MK into an early lead, but Chris Whelpdale (pictured) equalised with a terrific 27th minute diving header. MK went on to pip Posh to top spot by five points. Both teams were promoted.
3.
September, 2008: MK Dons 1, Posh 2. The following season in League One Ali Gerber gave MK a second-half lead only for young substitute Dominic Green (pictured) to inspire a brilliant Posh fightback. Green won a penalty which was converted by Craig Mackail-Smith and curled in the winner direct from a free-kick although predictions he would go on to play in the Premier League proved optimistic.
4.
January, 2009: Posh 0, MK Dons. Both teams were challenging for promotion from League One so a clash under the London Road lights was eagerly anticipated. Sadly MK manager Roberto Di Matteo set MK up to waste time from kick off with goalkeeper Willy Gueret (pictured) particularly irritating. Posh had the last laugh though as they were promoted as runners-up behind Leicester City while third placed MK lost in the play-off semi-final to Scunthorpe.