Last updated 21:21, May 23 2018
The assault happened in Paterson Street, Frankton, on Wednesday evening.
A man was attacked with a baseball bat on his Hamilton property, leaving him in serious condition.
Police and ambulance services were called to Paterson Street, Frankton, around 7.15pm on Wednesday night after reports of an assault.
"Males have entered the property and struck one of the occupants in the head with a baseball bat," Waikato district shift manager Senior Sergeant Will Loughrin said.
It's not yet known how many men came onto the property as part of the attack but it was more than one, he said.
St John Ambulance took one person to hospital in a serious condition, a spokeswoman said.
Police were investigating at the Frankton home on Wednesday evening.
Other people were home at the time of the incident, Loughrin said, and police were speaking to them.
It was not yet known whether the men behind the attack and their victim were known to each other.
Anyone with information which could help the investigation can contact Hamilton police on 07 858 6200.
Information can also be left anonymously via Crimestoppers on 0800 555 111.