A third person has died after a head-on collision on Wednesday night near Dannevirke in Manawatu.
Police say an elderly woman driving one of the cars and a girl, aged 2 in the other, died in the crash.
The toddler's father later died in hospital.
The child's mother and a passenger in the other vehicle are in Palmerston North hospital with injuries described as serious to critical.
State Highway 2 was closed for a time.