The non-native creature, which is about the size of a domestic cat, was filmed by a wildlife monitoring group at 05:30 on 17 March.
Stills from a night vision camera set up to track wildcats clearly show the nocturnal mammal standing on its hind legs and eating bait.
The public have been warned not to approach the raccoon as it could bite.
Stan Whitaker, SNH Wildlife and Non-Native Species Manager,  said: "Raccoons could cause millions of pounds worth of damage per year to the Scottish economy if they became established here.
"They could also cause significant damage to our native wildlife by preying on birds, small animals and amphibians.
"Raccoons aren't dangerous, but they may give you a nasty bite if cornered. The raccoon that has been recorded is an adult and roughly the size of a domestic cat."
He added: "Ideally, we would like to trap this raccoon and rehome it in a zoo or wildlife park.
"If you come across the raccoon, do not approach it, but please report it immediately to Scotland's Environmental and Rural Services."
Raccoons are listed as one of the top 50 invasive, non-native species in Scotland. Kept as pets and in zoos, there have been several escapes in the last few years.
They are considered a nuisance in their native north America,  as they damage buildings and gardens and forage in rubbish bins. They also carry wildlife diseases such as rabies.
In 2013, a raccoon called Ronnie spent three months on the run after escaping from a Perthshire wildlife park.
Conservation officers are hoping to catch a raccoon seen living wild in Garve in the Highlands.