A man was taken to Wairarapa Hospital with three stab wounds to his buttocks after an argument in a Masterton house on Tuesday night.
The man, aged 48, did not receive life-threatening injuries as a result of the multiple stab wounds, police say, but a 23-year-old man has been arrested and charged with assault using a weapon.
Senior Sergeant Warwick Burr said the alleged assault happened about 9.15pm on the east side of the town.
He said although the two were known to each other they were not father and son.
Mr Burr said inquiries into the incident were on-going, but the arrested man is expected to appear in court to answer the charge at a later date.