The second unnamed man, a resident of Georgia referred to as John Doe No 2 in court papers obtained by Reuters, claimed that Travolta rubbed his legs, touched his genitals and tried to initiate sex at a private appointment at the actor's room inside an Atlanta hotel on 28 January.
The allegations echo those of John Doe No 1, a resident of Texas, who filed the initial complaint earlier in May and accused Travolta of sexually assaulting him during a private massage at the Beverly Hills Hotel on 16 January.
'Absurd, ridiculous'
"This second 'anonymous' claim is just as absurd and ridiculous as the first one," said attorney Martin Singer, who represents the Hollywood actor.
"Our client will be fully vindicated in court on both of these absurd and fictional claims."
Travolta's spokesperson has called the lawsuit "complete fiction and fabrication."
More potential victims
The plaintiff's attorney, Pasadena, California-based Okorie Okorocha, told Reuters that since the initial complaint was filed last week, he has had many more potential victims come forward with similar complaints.
"I will file for every single victim. Mr Travolta has been able to evade justice, and he's going to challenge it with me. but I'm not afraid ... I'll stand up to him," said Okorocha.
He said that the men did not go to the police because they did not think the police would believe them.
Travolta, 58, rose to fame in the 1970s on the television sitcom Welcome Back Kotter, then became a movie star with hits such as Saturday Night Fever, Grease, and later, Pulp Fiction.
He has been nominated for two Academy Awards and has been married to wife Kelly Preston since 1991.