Health chiefs said the technology at four main hospitals across the Lothians was helping in the battle against MRSA and C.diff.
Figures released earlier this week revealed NHS Lothian was making strong progress on both, and is well on target to meet Scottish Government goals by the end of the year.
The UV light of the glow box shows germs clearly, allowing the visitor, patient or staff member to then take action.
Diane Loughlin, health promotion lead, said: “The response to this programme has been extremely positive so far.
“We are pleased to see this kind of activity within the hospital, encouraging everyone to wash their hands.”
Boxes are installed at the ERI, the Western General, the Sick Kids and St John’s Hospital in Livingston.