Since the early 1980's graffiti emerged in Mexico City, from the United States and passing through Tijuana and Guadalajara, as one of the most consistent cultural manifestation, but scarcely explored. This practice was carried out by an extensive community, originally underground, which soon transformed into an urban phenomenon of enormous dimensions. Codex ±An approximation to the graffiti in the city of Mexico, discusses the origins of graffiti as well as the complex socio-cultural relationships that surround it. The research, carried out by means of a meticulous field work, shows the work developed by graffiti painters and their crews for more than thirty years, and follows a line from the origins of graffiti up to present days along with interviews of 21 featured protagonists such as Humo, Neuzz, Retén, Sr. Niuk and Peque to bring the reader to the world of graffiti. Includes a glossary of terms used by the graffiti artists.