Rat Poison is a poison commonly used to remove the infestation of rodents in various places. The contents include arsenic, barium and thallium, very poisonous substances.
- "Old rat poison. The ingredients consist of arsenic, barium, and thallium; extremely poisonous substances."
In the earlier games, this form of poison was often the only poison available before the Poison Syringe was added. In HITMAN™, the poison now serves a different purpose; mixing it into a target's drink/food to get them alone. Upon indigestion, the target feels the need to vomit, and heads to the nearest Bathroom, where they can be killed/subdued.
- Rendezvous in Rotterdam: Between two dumpsters near the garage.
- Deadly Cargo: In the basement of the strip club.
- Slaying a Dragon: In a sewer.
- The Seafood Massacre: In a sewer near the back of the restaurant.
- Hunter and Hunted: On a food kiosk on the opposite side of the pagoda from the start in the Chinese New Year, directly across from the Katana.
- Attack of the Saints: Below 47's starting location in the Parking Lot.
- Freeform Training: On one of the rooms in the lowest deck of the ship.
- The Final Test: In one of the toilets.
- World of Tomorrow: On the third level in the guard room, in the room in the most southern part of mansion, in the ice cream cafe, on the kitchen.
- A Gilded Cage: In the room in the center of parking.
- Unlike in the previous games, the poison is not lethal in HITMAN™. In reality, a human can survive Rat Poison if they manage to get it out of their system, usually by vomiting. It's effectiveness against rats comes from the fact that rats cannot vomit, and thus are unable to get it out of their system.