The man was taken to hospital and a car was also damaged in the incident, though police have said it was unclear how.
Officers were called to reports of a disturbance on Trafalgar Court, Tividale, at around 8.30pm on Friday.
The investigation into the incident started has now started, with police ruling out the use of guns in the assault.
A spokesman for West Midlands Police said: "A boy and girl aged 17 and a 42-year-old man were assaulted. A car was also damaged, but at this time it’s unclear how.
"There is no evidence of guns being fired.
"If you know what happened, send us a message via Live Chat on our website west-midlands.police.uk or call the charity Crimestoppers anonymously on 0800 555 111 – you may be entitled to a reward.
"Please quote investigation number 20/234514/22"
A West Midlands Ambulance Service spokesman said: "We were called at 8.38pm to Trafalgar Court, Tividale, Dudley on he 18th February.
"One ambulance attended and we treated one man on scene before he was taken to hospital for further care."