Two skiers are in Christchurch Hospital after suffering head injuries when they collided at Mt Hutt ski field.
A St John Ambulance spokesperson says the incident happened at about 11.30am on Monday.
Mt Hutt ski area manager David Wilson says the two intermediate-skilled skiers collided as they skied towards the base of Mt Hutt.
One of them is in his 50s, the other in his 60s.
The ambulance service says they were flown by helicopter to Christchurch Hospital's emergency department as a precaution.
Mr Wilson says the men were lucky they were wearing helmets, otherwise they could have more severe injuries.
He says collisions are common on ski fields.
He says the field is not that busy, with fewer than 1500 people skiing on Monday.