The man is described as Caucasian, between 20-25 years-old, with short dark hair and short dark stubble on his face, approximately 5 feet 10 inches tall, and slim to medium build.
He has a distinctive tattoo by his left eye described as rays of the sun coming out in five lines.
"I caution the public to not approach the man but if they see him please call 111 immediately," Sgt Irvine said.
The man was wearing a black hooded sweatshirt with a zip at the front which was baggy and reached to his mid thigh, and black track pants with white stripes down the side of the legs. He was also wearing black fingerless gloves.
"This is a very unique tattoo and would be easily recognisable," Sgt Irvine said.
"We are hoping someone has seen the man fleeing or seen him exit the hospital and I strongly encourage anyone with information to contact police."
The chaplain sustained minor injuries and is in a comfortable condition.
"He thanks everyone for their well wishes but has requested privacy at this time," Sgt Irvine said.
Anyone with information is asked to contact the New Plymouth Station on (06) 759 5500.
Alternatively information can be provided anonymously via Crimestoppers on 0800 555 111.