We report the first occurrence of Arianta arbustorum (Copse Snail) on Prince Edward Island, expanding its well-established presence in eastern Canada. Although listed as an exotic mollusc for which prevention of introduction to the US is a priority, the evidence from Canada to date suggests a low pest potential for this species. It is unlikely that eradication efforts in North America would be effective; thus, the Copse Snail may be a poor candidate for pest-prevention efforts in the US.