The Office of Tobacco Control says 97% of workplaces are fully complying with the workplace smoking ban introduced more than five years ago.
In its latest annual report, the organisation says almost 25,500 inspections were carried out by environmental health officers last year and just 24 offences were detected.
Elsewhere, the OTC is also warning that it will be clamping down on shops that display point-of-sale tobacco advertising once a ban on such displays comes into effect from July 1.