Model of Aztec tianguis at the National Museum of Anthropology
The tradition of buying and selling in temporary markets set up either on a regular basis (weekly, monthly, etc.) is a strong feature in much of Mexican culture and has a history that extends far back into the pre-Hispanic period.
 It was the most important form of commerce in the pre-Hispanic era, and after the
Spanish Conquest, the Europeans mostly kept this tradition intact.
 Market areas have been identified in ruins such as
El Tajín in
Veracruz, and a number of pre-Hispanic towns were initially founded as regional markets, such as
Santiago Tianguistenco and
 The word “tianguis” derives from the Nahuatl word
tiyānquiztli “open air-market”, from
tiyāmiqui “to trade, sell”. The most important markets, such as the one in
Tlatelolco, were set up and taken down every day of the week. This market served about one fifth of the population of
Tenochtitlan (Mexico City) before the Conquest and had its own governing system, which included a panel of twelve judges to resolve disputes.
 Today, one of the most visited exhibits in the
National Museum of Anthropology is the model of the pre-Hispanic market such as the one in Tenochtitlan.
From the time of the Conquest to the present, many tianguis, especially in rural areas, have continued to operate much in the same way as before, with only changes in merchandise that reflect changing customer needs.
 In the cities, especially Mexico City, the history of these markets is filled with examples of attempts to regulate them and push them away to other places, with mixed success. The
Zocalo, or main plaza of Mexico City, was the scene of a number of efforts to clear the area of
street vendors, and establish permanent markets in or near the plaza such as the Parian. In all these cases, vendors eventually retook the plaza
 This problem was again tackled in the 1990s as part of an effort to revitalize the historic center of Mexico City. Despite much initial resistance, the area has been free of street peddlers since that time.
 Much of the tianguis business that used to be done in the Zocalo has now moved to other places such as the Tepito neighborhood.
Tianguis in Mexico City in 1885
Hall in the La Merced Market in Mexico City
In the 20th century, local governments in Mexico have promoted municipal or public markets or “mercados” to better regulate the selling of goods traditionally available in tianguis. In Mexico City, some of the better known of these markets are
Abelardo L. Rodriguez Market and
 La Merced is located in an area that had been a huge tianguis for most of the colonial period as it was located at the edge of a lake (now drained).
 The Abelardo L. Rodriguez Market was specifically built by the government in the 1930s to try to “modernize” the sale of produce and other staples. It went as far as having a daycare center and a theater and commissioning
Diego Rivera to supervise the painting of murals inside. These murals can still be seen today.
 However, these efforts have not eliminated the tianguis tradition; in fact, the number of such informal markets (5,836,000) far surpasses the number of mercados (2,810,000). In Mexico City alone, there are 317 mercados versus 1,357 tianguis. One reason is that many of these mercados are not well-maintained and few new ones have been built since the 1970s.
The tianguis is part of the so-called “
 even though many of the “informal” vendors are well enough known and established to offer services such as layaway.
 While many establish stores consider the tianguis to be damaging to their businesses,
 many Mexican consumers see both sectors as complementary.
Surveys of consumers have shown that many Mexicans buy from tianguis because of the frequent lack of bargains, social interaction, and customer service in formal stores. According to one survey, over 90% stated that they have bought merchandise from a tianguis, with the average family spending about 300 pesos per visit. The most common items sold in tianguis include groceries, beauty supplies, clothing, appliances, electronics, prepared foods, tools and used goods.
 About a third of Mexicans buy at least some of their clothing and shoes in tianguis.