Tijuana is the most populous city of the Tijuana metropolitan area.
Tijuana ( [ tiːˈwɑːnə ] ; [ tiˈxwana ] ) is the largest city in Baja California and on the Baja California Peninsula and center of the Tijuana metropolitan area , part of the international San Diego -- Tijuana metropolitan area . As the city has become a leading center in the country , so has the surrounding metropolitan area , a major industrial and paramount metropolis in northwestern Mexico . According to the 2010 census , the Tijuana metropolitan area was the fifth-largest in Mexico , with a population of 1,784,034 , but rankings vary , the city ( locality ) itself was 6th largest and the municipality ( administrative ) 3rd largest nationally .