Police were called to reports of disorder outside the Fox Inn, in Green Lane, Lye.
Two men, who were in their 30s, were taken to hospital for further treatment after the incident, while two others were treated at the scene for minor injuries.
Emergency services were called to the scene at around 11pm on Sunday.
A spokesman for West Midlands Police said: "We are investigating after being called to a disorder outside The Fox Inn in Green Lane, Lye, at just after 11pm on Sunday.
"Officers attended and found two men in their 30s had suffered head injuries which required hospital treatment but are not believed to be life-threatening or life-changing.
"Two other men also required treatment by paramedics at the scene for minor injuries.
"Enquiries are on-going, including a review of CCTV footage from the area."
A spokesman for West Midlands Ambulance Service said: "An ambulance that was passing the Fox Inn, Green Lane, Lye at 11:18 pm on Sunday evening was flagged down as it passed and the crew asked to examine two men who had been assaulted.
"The men had both suffered multiple but not life threatening injuries.
"After treatment at the scene, they were taken to hospital for further assessment."
Anyone with information is urged to call West Midlands Police on 101, quoting crime reference number 20/178553/21.
Alternatively, call Crimestoppers anonymously on 0800 555111.