Two women and four men are in custody after the alleged incident last night, Humberside Police said.
A spokesman said: "Six people have been arrested on suspicion of section 47 ABH and section 18 GBH following an incident in a Hull bar last night.
"Two men were injured during an alleged altercation which happened around 9pm at the premises on Silver Street in Hull city centre.
"They were treated in hospital for their injuries.
"The two arrested women and four arrested men remain in our custody at this time."