Trichocereus Pasacana is a tree-like cactus that gets up to 10 meters (30 feet) tall though the average height is usually a lot less. It can reach a diameter of 30-45 centimeters (10-15ft.) and has between 18-22 ribs. It has a lot of small, needle-like spines that can get up to 10-15 centimeters (4-6") in length. The mature form looks a lot different to its younger appearance.
The spines are yellow in colour and their length decrease with age. Old plants tend to have lesser spines than young ones and the early spine form is a lot stronger that the adult form. The flower is white and 10-15 centimeters (4-6") long. The flower has hairs on most parts and is covered with a dark brown wool.