A minority of health boards said the assault statistics included instances of verbal abuse.
In Waitemata, the highest-populated health district, physical attacks rose by 12 per cent last year but were less common than in 2010.
These included six physical attacks against dental staff and 163 acts of physical violence at the Waitemata forensics department over the past three years.
In Wanganui an employee was given 2 hours' ACC leave after being kicked and punched in the face at the Te Awhina mental health unit.
Southern District Health Board recorded verbal abuse and offensive behaviour such as spitting as assaults.
The board said some mental health patients did not have "language to describe what is happening to them and are sometimes deaf and/or blind and severely intellectually disabled.
"The forensic service admit patients because of their mental illness. The combination of mental illness, addictions and criminal behaviours are a challenge to manage in all environments."