The document management company alleges that Google has infringed upon its patent "System for automatically generating queries" with its AdWords and AdSense software.
It also claims that Google Maps and Google video violate a different patent, "Method and apparatus for the integration of information and knowledge," which has to do with updating Web pages based on user reviews.
Yahoo, Xerox claims, has infringed on its query patent with Yahoo Search Marketing, Yahoo Publisher Network and Y!Q Contextual Search. And the company further claims that Yahoo Shopping steps on its integration patent.
Likewise, Xerox says that Google's YouTube infringes upon its integration patent.
Xerox is seeking treble damages because it claims the defending companies are aware of its patents and that their infringement is willful.
"We have been in dialog with Google and Yahoo for some time about licensing these patents, without reaching a resolution," a Xerox spokesperson said in an e-mailed statement. "We believe we have no option but to file suit to properly protect our intellectual property."
Google's senior litigation counsel Catherine Lacavera, said in an e-mail, "These claims are entirely without merit, and we'll vigorously defend ourselves against them."
Yahoo offered a similar statement. "Yahoo does not believe we infringe and plans to fight this case," a company spokesperson said via e-mail.
Google and Yahoo both support the Coalition for Patent Fairness, a group that has been lobbying for patent reform.
Supporters of patent reform argue that the patent system hasn't been amended since 1952 and have been trying for several years to rally support for legislation to change the patent system.
The most recent proposed legislation, the Patent Reform Act of 2009, has been sitting in committee in the Senate for almost a year.
Update: Added comment from Yahoo.