More than 95% of reported dumped rubbish was cleaned up within five days during 2013/14.
This is compares with just over 92% the previous year and 91.3% in 2011/12.
Blaenau Gwent was the best performer in Wales, with a 100% clear-up rate within five days.
The figures are included in the latest national performance statistics for councils in key areas.
In total, 31,301 fly-tipping incidents were reported across Wales, which is a slight rise on the previous year.
The response rate ranged from 80.2% in the Vale of Glamorgan and 81.1% in Neath Port Talbot to 99.2% in Rhondda Cynon Taf, 99.1% in Caerphilly and 99% in Carmarthen.
Denbighshire recorded 2,206 fly-tipping incidents, clearing up 94% within five days.
But Kelvin Hughes, Denbighshire's senior environmental crime officer told the Daily Post there was inconsistency between how authorities log the data.
"We take the view that to the public it doesn't matter whose land it's on; Denbighshire looks untidy, and that's what we want to get away from, which is why we look at fly tipping on private land as well as public land which we're responsible for," he said.
Councils in Wales are getting better at clearing up fly-tipping, according to latest figures from the Welsh government.