A man suffered a broken jaw and two other men were taken to hospital after a disturbance at a Killamarsh pub.
Police were called to The Midland pub just after 8pm on Sunday, April 13.
On arrival officers found three men with injuries.
The men, aged 33, 27 and 24 years old, were taken to hospital for treatment for injuries including a broken jaw.
A fourth man, aged 26, suffered minor injuries.
It is alleged a group of men had returned to the pub following an earlier altercation and assaulted the victims.
Police are appealing for information and urge witnesses to call 101 or Crimestoppers anonymously on 0800 555 111.