The figure recorded by health boards is £2m over the last five years but the unit responsible for detecting crime in the NHS said that the true figure is likely to be many millions more.
BBC Scotland's NHS Thieves reveals the amount defrauded has risen 42% over the period. NHS Greater Glasgow and Clyde, saw the value of detected fraud soar from £148,000 to £341,000.
Programme filmed the work of NHS Scotland's Counter Fraud Services (CFS) as they pursued doc-tors, dentists, nurses and patients suspected of stealing from NHS Scotland's £11 billion annual budget.
The show reveals that the NHS is chasing a convicted dentist from Auchinleck, East Ayrshire, for more than £782,000 after he profited from unnecessary treatments and charged for prec-ious metals for crowns while using cheaper materials.
It also highlights the case of a worker at Glasgow's Yorkhill Children's Hospital, who stole medical equipment to sell on eBay, banking an estimated £75,000.
Only 5% of people repor-ted for fraud in the last five years have been convicted, according to the programme.
CFS head Gordon Young told the show: "Frauds are committed by a small minority. It's a hidden crime, it's a difficult crime to quantify."
Scotland's NHS Thieves is on BBC One Scotland tonight at 10.35pm.