Uruguayans have taken voting very seriously. Voting, which was obligatory, was not restricted by race, sex, religion, or economic status. Other rules governing suffrage included mandatory inscription in the Civil Register and a system of proportional representation. These rules also included prohibition of political activity (with the exception of voting) by judicial magistrates, directors of the autonomous entities, and members of the armed forces and police. In addition, the president of the republic and members of the Electoral Court were not permitted to serve as political party officials or engage in political election propaganda all electoral boards had to be elected a two-thirds vote of the full membership of each chamber was needed to adopt any new law concerning the Civil Register or elections and all national and local elections were to be held on the last Sunday in November every five years.

Uruguay's electoral processes were among the most complicated known. The unusual Uruguayan electoral system combined primaries and a general election in one event. Primary and general elections combined proportional representation with a "double simultaneous vote" (doble voto simultáneo). This system, as established by the Elections Law of 1925, allowed each party's sub-lemas, or factions, to run rival lists of candidates.

Traditionally, under Uruguayan law the results of political elections were tabulated in an unusual fashion. Under the 1982 Political Parties Law, each party was allowed to present three tickets, or single candidates, each representing a different sub-lema, for executive and legislative posts, and these factions did not need the party's approval of their candidates. A voter selected a faction and a list of candidates within that sub-lema. The votes of all the factions were given to the party (lema) to which they belonged, and the presidency went to the candidate of the sub-lema that received the most votes within the winning party. Thus, even if a given ticket garnered more votes than any other slate running for election, it could not win unless its party also won. The governing party was actually the majority group within the party that won the last elections. The disadvantages of this system were that it discouraged intraparty selectivity in choosing presidential candidates, often allowed politicians who received only a minority of the vote to rise to power, blocked the rise of new parties and new leadership while encouraging fractionalization, and often resulted in a multiplicity of alliances or combinations of national and local candidates for office.

Election of members of the General Assembly was even more complicated. Election of the ninety-nine members of the Chamber of Representatives was based on the population in the country's nineteen departments, whereas the thirty members of the Senate were elected at large from the nation. Seats were allocated on the basis of each party's share of the total vote, but each party usually had various lists of candidates, among whom prior agreements had be8b8 been made to unify or transfer votes. As a result, there have been frequent complaints that voters never knew for whom they were ultimately voting in the congressional races. Electoral fraud, however, was precluded by the traditional method of decentralized vote-counting at thousands of vote-counting tables.

In addition, the Electoral Court supervised the entire registration and voting process, registered parties and candidates, had final jurisdiction in all election disputes, and supervised the functioning of the various departmental electoral boards. It also supervised the National Electoral Office in Montevideo, which had the responsibility for organizing and maintaining the Civil Register of all eligible voters in the country. One Electoral Court existed at the national level and one in each department capital.

Before an election, the General Assembly allocated a sum of money for the Electoral Court to distribute among the political parties in proportion to the number of votes a party received in the last election. These funds helped to defray campaign costs. Party-proposed ballots had to be presented to the Electoral Court at least twenty days prior to an election. After making the final verification of ballots, the Electoral Court could annul an election, but only if gross irregularities were found.

Data as of December 1990