[1] It elects one deputy to the lower house of Congress for each three-year legislative session by means of the first-past-the-post system.

Votes cast in the district also count towards the calculation of proportional representation ("plurinominal") deputies elected from the third region.

Under the National Electoral Institute's 2022 districting plan, which is to be used for the 2024, 2027 and 2030 federal elections,[4] the 3rd district covers the entirety of the municipality of Isla Mujeres and 321 electoral precincts (secciones electorales) in the neighbouring municipality of Benito Juárez.

[5] The district's head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the city of Cancún, the municipal seat of Benito Juárez.

From 2017 to 2022, the 3rd district had its head town at Cancún and it comprised 242 precincts in the municipality of Benito Juárez.