The Left Democratic Front Government, which was in power from 1987, decided to seek a fresh mandate one year ahead of the expiry of its term. The decision was prompted by the announcement of the elections to the Lok Sabha (Lower House of Parliament) and the Front's good showing in the elections to the local bodies held in the previous year. (The Lok Sabha elections had become necessary with the fall of the S. Chandrasekhar Government at the Centre).

As in the previous elections, the Left Democratic Front (LDF) and the United Democratic Front (UDF) were the main contesting fronts. However, the main faction of the Kerala Congress, led by Mr. P. J. Joseph, had left the LDF and joined the LDF. At the same time, the Communist Marxist Party, formed by Mr. M. V. Raghavan, who was expelled from the CPI(M) over policy differences, joined the UDF.

Though the elections were scheduled to be held on May 23, 1991, it was postponed to June 18 following the assassination of the former Prime Minister, Rajiv Gandhi, on May 21. The elections saw the LDF losing power and the UDF returning to power after four years.

The total electorate for 1991 election was 1,96,57,974.  Thus, there is an increase of about seven lakh voters.  About 73.46 per cent (14433354) of the electorate exercised their franchise.