The pair were left with whiplash after a minor accident in Los Angeles early yesterday after they left a studio following a long recording session.
According to reports, US rapper Will.i.am was driving a Cadillac which hit a parked car while Miss Cole was in the front passenger seat.
Both soon assured fans they were fine. Will.i.am tweeted: "Car accidents are not dope ... I'm glad I'm o.k£wiplash."
He added: "We're fine. Cheryl Cole (and I) were coming back from the studio but she and I are fine ... just a little wiplash."
Miss Cole, who is dating LA-based dancer Tre Holloway added: "Don't worry me and @iamwill are fine, promise x"
The pop queen was left shaken and bleeding after the accident about 3.30am.
Eyewitnesses said Will.i.am's airbag inflated, hitting him in the face and causing his nose to bleed.
However, there seemed to be no safety system on Miss Cole's side and it is thought she banged her head on the luxury car's dashboard.
Blood from her nose was seen pouring over her lips and she was clutching her face.
Will.i.am, 37, checked the Girls Aloud star, 29, was not injured and leaned across to stroke her head.
Police arrived at the scene before Will.i.am was taken to hospital. He had a full check-up at nearby Cedars-Sinai hospital, while Miss Cole was treated at the scene and did not need to go to hospital.
Will.i.am was later seen leaving hospital in a neck brace with blood stains on his jeans. It is believed the pair were working in a studio before the crash.
Miss Cole, who beat life-threatening malaria, which she contracted on a holiday to Tanzania two years ago, recently described the Black Eyed Peas singer as "family."
Her first solo performance apart from Girls Aloud was on the rapper's single Heartbreaker in 2008. He was also her Cole's album 3 Words in 2009. He is expected to join her on her UK tour which starts in October.