The truck was reversing into a loading dock, but the driver of the truck couldn't see the shuttle. The driver of the truck was cited for "unsafe backing".
The accident is believed to be the fault of a human truck driver who emerged from a side alley and failed to stop his vehicle. AAA plans to donate $1 per passenger to the Las Vegas Victims' Fund, for a minimum of $100,000.
The shuttle was pulled from service for the rest of the day, but the city plans to continue the pilot project.
According to News 3 Las Vegas, the driverless shuttle collided with a delivery truck within its first hour of operation in downtown Las Vegas.
City spokesman Jace Radke said: "The shuttle did its job in that the sensors hit on the truck, knew the truck was coming and stopped as it was supposed to do".
"We believe our Las Vegas pilot will allow the public to experience this exciting technology for themselves and allow their voices to be heard as AAA studies how autonomous transportation can be safely deployed for public use".
Developed by French company Navya, it uses Global Positioning System, electronic kerb sensors and other technology to find its way at no more than 15mph.
It's the first time the shuttles have been tested in the USA but they have already arrived in London, where the former Olympic park in Stratford began a trial by Navya and Keolis in September. The goal is to have at least 250,000 people ride the driverless shuttle. It seats eight people and has the ability to immediately brake automatically or manually in case anything crosses its path. However, it sheds light on the various issues that may arise when such cars navigate.
Navya has a fleet of 50 autonomous shuttle buses deployed worldwide, and says that it has carried over 200,000 passengers so far.