It has an area of 156.2 square kilometres (60.3 sq mi)[6] and borders the municipalities of Tlalnepantla de Baz, Tecámac, Coacalco de Berriozábal, Jaltenco, Acolman, Texcoco, Atenco, and Nezahualcóyotl and the Mexico City borough of Gustavo A. Madero.

Animals include small mammals, like mice, rabbits, gray squirrels, and gophers, and birds, such as cenzontles and sparrows.

[9] Notable tlatoque include:[citation needed] During the Aztec empire, the Mexicas used the town to control trade routes going north.

[3] Ecatepec was considered a "República de Indios" (Indian Republic) in 1560, allowing it to maintain some autonomy and keeping the succession of tlatoanis or chiefs.

[8] National hero José María Morelos y Pavón was executed in Ecatepec in 1815 by the Spanish Army during the Mexican War of Independence.

[8] Ecatepec experienced exponential population growth from 1970, as a result of rural migration to the Valley of Mexico.

The Roman Catholic Diocese of Ecatepec is the newest in the country, erected on June 28, 1995, around the Sagrado Corazón de Jesús Cathedral.

[10] In April 1995, the remains of a mammoth were found in Colonia Ejidos de San Cristóbal, where the ancient lakes of Xaltocan-Ecatepec and Texcoco came together and where the Aztecs build a dam to keep the fresh and salty waters separate.

[11] Almost all of the population (99.9%) of the municipality lives in San Cristóbal Ecatepec, the third most-populous city in Mexico.

[13][14] Two regional shopping malls, Plaza Las Américas and Multiplaza Aragón (Mexico's busiest as of 2018),[4] both with multiple hypermarket and department store anchors, are located in Ecatepec.

Ecatepec, due to its population density, is one of the municipalities with the highest levels of infrastructure in the State of Mexico.