Police said the serious assault happened in the Garvaghy Road area of Portadown in the early hours of this morning (Sunday, 13 August).
Police received reports shortly before 4:30 am that two men aged 22 and 25 were assaulted by men brandishing weapons and both received head injuries due to the attack.
They are currently being treated in hospital as a result of this.
A car was later found burned out in the Drumnagoon Road which may have been related to the incident.
Police have been conducting searches of the area today and have arrested a man aged 50 on suspicion of attempted murder.
Detectives would appeal that anyone with information contact them at Lurgan station on 101 quoting reference 390, or if you wish to remain anonymous alternatively Crimestoppers on 0800 555 111