Unison said 12,618 assaults on doctors, nurses, paramedics and other healthcare staff had been recorded this year, a rise of almost 15% compared with the total number of 10,974 in 2012.
Overall, the number of assaults against public sector staff had dropped slightly year on year, to 33,689 in 2013. This was 1055 less than in the year before.
The biggest fall was in the number of attacks on police since the single force was created in April, dropping by more than 3000 to 6187.
However, assaults on local government workers increased by 730 to 14,879, with teachers and school support staff among the worst affected.
Unison said it was concerned that public spending cuts had contributed to the rise in some attacks and suggested there were fears that intimidation towards housing staff could turn violent more frequently, particularly in light of protests at the introduction of the so-called bedroom tax.
Unison's Scottish Organiser Dave Watson said: "The biggest increase in violent incidents is happening in those services that have suffered staffing cuts. Workers are stretched too thinly, dealing with the public who are coping with cuts in the services they rely on. This is a toxic cocktail that is putting workers at greater risk of violent assault."
Scott Donohoe, chairman of Unison Scotland's Health and Safety Committee, added: "These numbers only cover recorded incidents - the tip of the iceberg of misery for many staff."