[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 first region.
[2][3] 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 western portion of Ciudad Juárez and the municipality of Juárez, together with the adjacent municipalities of Ascensión and Janos.
[5] Its head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the city of Ciudad Juárez.
[7] The districting scheme in force from 1978 to 1996 was the result of the 1977 electoral reforms, which increased the number of single-member seats in the Chamber of Deputies from 196 to 300.