Three men were lucky to escape a car uninjured after it hit a kangaroo and was engulfed in flames, sparking a grassfire on the Monaro Highway in New South Wales.

That is according to Michelago Rural Fire Brigade Captain Brent Wallis, who praised firefighters for quickly extinguishing the blaze shortly after 7:00am on Monday.

Mr Wallis said the men were about 4 kilometres north of Michelago when the car hit the kangaroo, with the impact setting the engine bay on fire — something the captain said he had seen only a handful of times in 20 years.

The men quickly got out of the car and called triple-0, with three firefighting trucks responding within 10 minutes.

"The flames were about 3 to 4 metres high," Mr Wallis said.

"I was surprised no-one was injured."

"The young men were fine and walking around, they actually tried to helped us put out the grass fire … but shock is a thing that comes later."

The car and nearby grassland were left charred and blackened. ( Supplied: Brent Wallis )

Mr Wallis said he was thankful for the fast response.

"The wind was blowing straight up the hill from the south, which made the fire move fairly quick," he said.

"But it was manageable — with the dry conditions, the only fuel at the moment around that area is beside the road as the paddocks have been stocked with sheep."

Monaro Highway was closed for 30 minutes following the fire.

'Everyone is on edge'

The scarce availability of kangaroo food on paddocks was causing many of the animals to migrate to long grass beside highways, Mr Wallis warned.

"More than usual are even migrating into urban areas just to get some food," he said.

"So be cautious if you see a kangaroo and remember not only is there other traffic on the road, but there is wildlife."

Mr Wallis said the last thing firefighters needed was another bushfire to add to the string of blazes that had devastated parts of the state in recent weeks.

"It is a different year with no rain through the winter," he said.

"It's a lot more drier coming into the spring that what we've had in the past 20 years, so everyone is on edge and ready to go."