A Wairoa man in his early 20s was airlifted to Hawke's Bay Hospital on Friday after being thrown from the quad bike he was riding on a rural property at Ohuka.
The service was called just after 4pm after the man was left with chest and abdominal injuries.  The machine is believed to have rolled.
The incident added to a growing list of injury accidents laid at the wheels of quad bikes, or ATVs (all-terrain vehicles).
Figures released by the Accident Compensation Corporation in June showed that in the rural sector tractor, cattle and quad bike accidents cost about $12.4 million in claims each year.
A study by Otago University estimated that in any given year farm workers would lose control of quad bikes on more that 12,500 occasions - resulting in 1400 injuries.
There have been calls for mandatory safety helmet use on quads, along with proposals for roll cages and seat restraints.