A man was dragged by his horse during the Methven Rodeo in central Canterbury on Saturday.
The event's organiser, Warwick Bell, says the man was riding bareback and was bucked off before got caught up in the horse's reins.
He says the man was dragged around for about 30 seconds.
Mr Bell says the rider was taken to Christchurch Hospital by helicopter, suffering serious bruising .
The hospital says he is in a serious but stable condition.