[1] It elects one deputy to the lower house of Congress for each three-year legislative period 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.

It comprises 27 municipalities:[5] The district's head town (cabecera distrital), where results from individual polling stations are gathered together and tallied, is the city of Valladolid.

[7][8] Between 1996 and 2005, the district's head town was at Valladolid and it covered an area broadly similar to its 2005 configuration, but with more of the northern coast and less of the south-eastern border with the state of Quintana Roo.

[8] 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.