A woman from Coffs Harbour has been convicted under new laws which make it an offence to smoke with a child in a car, but has escaped a fine.

The 31-year-old was caught by police in August smoking in a car in which her three-year-old child was also a passenger.

She is one of the first people to be charged under the state's tough new anti-smoking laws, which are aimed at protecting children from second-hand smoke.

The penalty for anyone caught smoking in a car with children is an-on-the spot fine of $250.

Yesterday magistrate Judith Fleming convicted the woman of the offence but did not fine her.

The new anti-smoking laws came into force in New South Wales on July 1.