Eighteen complaints about child smacking were investigated by police in the six months to June 21.
They were among 456 instances of child assault attended by officers.
Only one of the 18 smacking incidents resulted in prosecution, 12 in a warning and five in other or no further action.
There were 58 cases involving "minor acts of physical discipline". Nine resulted in prosecution, 38 in warnings and 11 in other or no further action.
The smacking prosecution involved a child being smacked at least five times on the buttocks with an open hand. The smacking was witnessed and reported to police by a neighbour.
The offender had a prior history of assaults and police laid a charge of domestic common assault.
The defendant was ordered to come up for sentence if called upon by the Court during the following year.
There have been five smacking prosecutions since section 59 of the Crimes Act was amended in June 2007 and the number is rising.
"It is likely that this is due to an increase in incidents being reported to police," says Assistant Commissioner Malcolm Burgess.
"The numbers in this review are in line with previous reviews and police continue to use their discretion when dealing with section 59 incidents.
Police will continue to report on the impact of the amendment until June next year.
However lobby group Family First says "nearly 500" families have been investigated by police for allegations of smacking or minor acts of physical discipline, yet only seven per cent of them were serious enough to warrant charges being laid.
"A law is obviously a 'dog's breakfast' when there is such a high rate (93 per cent) of cases warranting no further action by the police," said spokesman Bob McCoskrie.
"It seems incredible that we are wasting time investigating hundreds of families who obviously don't warrant that investigation, ... and are diverting valuable police resources from serious crime and rotten parents where actual abuse is happening.
"What is concerning in the figures is that the serious 'child assaults' show a 60 per cent increase - with 206 being recorded in a 6-month period in 2008 and that figure rising to 332 in the latest 6-month period.
"We quite obviously have not even begun to tackle the at-risk families with preventative measures. And, tragically, our child abuse death rate continues unabated," said Mr McCoskrie.
Family First said it continues to call for an amendment to the anti-smacking law to clearly define what is reasonable physical correction, to decriminalise non-abusive smacking, and to then target the country's vital police resources at rotten parents who are abusing their kids.