The members are elected via a mixed-member proportional representation system, with a minimum of 5% vote share to receive any seats.

In Hesse, voting in Landtag elections is available for every German citizen aged 18 or over, who has primarily resided in the state for at least three months.

On 22 November 1945 the constitution for Greater Hesse (Staatsgrundgesetz des Staates Groß-Hessen) was introduced.

The SPD achieved majority and the CDU, the former partner in the grand coalition, lost close to 60% of their seats.

On 14 December 1950 the former Minister of Justice, Georg August Zinn (SPD), was elected as Minister-President of Hesse.

The SPD lost its absolute majority in the third election on 28 November 1953, but governed in a coalition with the "All-German Bloc/League of Expellees and Deprived of Rights", a party representing the victims of the post-war expulsion of Germans.

The SPD lost its majority but agreed on a social–liberal coalition with the FDP, and Albert Osswald was reelected.

On 11 May 1981, deputy Minister-President Heinz-Herbert Karry was assassinated by terrorists in his flat in Frankfurt am Main.

Himself hard-pressed by activists in his car, Börner, previously a learned roofer, at the time said that 40 years ago, he would have answered such attacks directed at his person — meaning the anti-airport-activists (the later Greens) — with "roof battens".

After the end of the social–liberal coalition in federal government, the FDP was not able to reach more than 5% in the Hessian Landtag, and so won no seats.

The snap election on 25 August 1983 saw the return of the FDP to the Landtag, but neither the CDU nor the SPD won a majority.

The vote on 20 January 1991 was as close as the last one, but this time the SPD and the Greens obtained slightly more seats.

One of the main reasons given for this result is an unpopular red–green legislative project aimed at granting citizenship to aliens.

[5] In order to put a stop to this project, the CDU organized a campaign and collected more than 5 million signatures.

Andrea Ypsilanti, leader of the SPD, had promised several times during the electoral campaign not to work together with the new leftist party Die Linke (The Left).

A few weeks after election day, she was tempted to go for a SPD–Green coalition supported by The Left but under opposition from MP Dagmar Metzger (SPD) decided not to renege on her promise not to pursue such a venue.

After a second unsuccessful attempt by Ypsilanti to take power, all parties agreed to dissolve the Landtag and call for early elections on 18 January 2009.