Two women were taken to hospital following the collision.
Gardaí are appealing for witnesses to a serious crash in Westmeath yesterday evening.
The two-car collision occurred on the N4 in Rathowen shortly after 4pm.
The driver of one vehicle, a woman in her 40s, was airlifted to Tallaght University Hospital.
Another woman, aged in her 60s, who was driving the other car, was taken to Tullamore Regional Hospital.