According to the survey of online adult consumers, AOL was rated the least-trusted company on the Internet when compared to Microsoft, Amazon.com, banks, brokerages, large retailers and credit card companies.
Some 37% of respondents gave AOL very poor marks in terms of trust, whereas 29% of those polled said they were distrustful of Microsoft.
A mere 15% of respondents said they had a high level of trust in AOL, compared to 17% for Microsoft.
The survey results come as the two Internet powerhouses are duelling to attract consumers for their rival services, one of which is instant messaging. While AOL scored highly for its instant messaging service, Gartner reported that loyalty among AOL's messaging users was limited.
The survey asked AOL users whether they were tempted to switch to Microsoft's MSN Messenger when it appeared on their screens as they were connecting to the Internet. Nearly one-third of respondents said that they were "not sure" if they would switch, while 4% said they intended to change to the Microsoft service.
Although almost two-thirds of those questioned said they would remain with their current service, the research showed that most users would take the path of least resistance and sign up for the service that was easiest to access.
Avivah Litan, the Gartner vice-president and research director, said: "When it comes to snaring more instant messaging customers, Microsoft is not facing the sort of entrenched and loyal AOL customer base that one would imagine."
In more disappointing news for AOL, Microsoft also rated higher on its Internet service provider and e-mail services.
The research noted that the survey results pointed to online security and privacy as being two of the most pressing concerns facing consumers, implying that trust will be a large factor in the take-up of new Internet services.