It begins along the Tecate Divide in the In-Ko-Pah Mountains, near Live Oak Springs.
West of Tecate it flows through a gorge and briefly re-enters the US where it combines with Cottonwood Creek to form the Rio Alamar, a tributary of the Tijuana River which it joins in Central Tijuana.
The portion of Tecate Creek in Mexico is about 29.9 kilometres (18.6 mi) long.
Combined with Campo Creek in the US, it is 57.5 kilometres (35.7 mi), making it one of the longest tributaries of the Tijuana River.
This article about a location in the Mexican state of Baja California is a stub.