In a meeting between two unbeaten teams at Borussia Park, neither was able to do enough to secure three points and move within one place of leaders Bayern Munich.
The hosts carved out the first opportunity of the match, Raffael forcing Loris Karius into a smart save from 10 yards in the fourth minute.
Lucien Favre's men did not have to wait long for the opening goal as Germany international Max Kruse broke the deadlock after quarter of an hour.
However, Mainz drew level in the 31st minute when on-loan Borussia Dortmund forward Jonas Hofmann converted from the penalty spot after referee Manuel Grafe had penalised Julian Korb for handling in the area.
Monchengladbach had claims for a spot-kick of their own waved away when Patrick Herrmann went to ground in the area, before a goalless second half saw the match finish all square.
Mainz now lie sixth, having drawn all bar two of their seven games this season, and Monchengladbach are two points better off in third, behind Hoffenheim on goals scored.
Elsewhere on Sunday, Wolfsburg made it three league wins in four matches and climbed up to seventh with a 1-0 triumph over Augsburg at Volkswagen Arena.
The only goal of the game came from centre-back Naldo in the 58th minute, the 32-year-old producing a superb strike into the bottom left-hand corner.
