There were 13,957 incidents of violence against staff in the nine months to December 2015, figures obtained by Scottish Labour reveal.
The previous full-year data, for 2014/15, show that 22,771 incidents of violence took place.
The Scottish government said "perpetrators must be dealt with in the strongest possible terms".
Scottish Labour has called on the Scottish government to ensure that those who attack staff are prosecuted and to do more to minimise violence against staff.
The party's public services spokesman Dr Richard Simpson said: "No-one should face the threat of violence for doing their job.
"Our NHS staff are Scotland's unsung heroes having dedicated their careers to helping others and saving lives.
"We learned this week that more working days are being lost due to staff stress, but these new figures should concern us all."
He added that people who attack NHS staff should face tough penalties.
"The SNP government must work with health boards, trades unions and staff to ensure that the conditions exist where such offences are minimised - and also to ensure that those who are violent are properly prosecuted," he said.
"Many people will question if a fine is the most appropriate way to deal with assaults on NHS staff."
Health Secretary Shona Robison said: "Attacks against our NHS staff are despicable and the perpetrators must be dealt with in the strongest possible terms.
"No-one should be the victim of abuse or violence while at work. We continue to encourage all NHS organisations to support criminal proceedings against anyone who assaults our staff."
She said the Emergency Workers Act includes a penalty of up to 12 months' imprisonment, a Â£10,000 fine, or both.
"In 2008 this government extended the act to include GPs and doctors, nurses and midwives working in the community," she added.
"Enforcing this extended law, and working with NHS boards, staff and trade union representatives has helped to bring down the number of attacks and improve workplace safety.
"The 2015 NHS Scotland staff survey found a 10 percentage point reduction in the number of staff who had experienced a physical attack since 2008.
"NHS staff care for the health of our country and that's why we must all be ready to stand up for them."
Almost 14,000 assaults have been carried out on NHS Scotland staff in the last nine months, new figures show.