£15,000 has been paid in parking fines since a company was appointed to check cars at Jersey's sports centres.
Hundreds more penalty notices haven't been paid.
Since September, a private firm has been monitoring the car parks at FB Fields, Grainville, Langford and Springfield - to stop cars being left overnight, dumped or spaces taken by people not using the facilities.
As of January 18th, around 620 tickets had been issued, with more than half of them (365) still unpaid.
£15,010 has been collected so far, of a potential total of more than £37,000 from those ticketed.
The States says the money goes towards the upkeep of the sports facilities, and it pays the enforcement company £600 a month.
Six vehicles have been identified as abandoned and will be towed.
Motorists are being reminded to display a disc showing their time of arrival.
Monitoring at Les Quennevais and Fort Regent is being done by on-site staff.