About 40 dope smokers lit up doobies and cones at Yatton Park on Saturday afternoon as part of J Day.
Organisers and supporters describe J Day as an international day celebrating cannabis culture and protesting against the failed war on drugs.
A 23-year-old Tauranga woman at the event said she started smoking the drug at the age of 18 after a lifetime of chronic illness.
"I have lupus, which is the deterioration of the bone and muscle. It's basically attacking my body from the inside out."
She was born with the disease, which usually only affected people from the age of 30, she said.
Since childhood she had suffered from arthritis, alopecia, and carpal tunnel.
"All my life I have been living on codeine, tramadol, morphine pills. All the hard-out painkillers and it's so bad for your body those pharmaceuticals, they are not good for your stomach lining and I was getting a lot of issues through that.
"So I started smoking marijuana and I am so much better. I sleep better, I function better, I am able to have a full-time job and run my own business.
"I couldn't do that before. I couldn't move. I couldn't get out of bed. I was stuck, cramped every morning."
She said she would only have a small joint or cone whenever necessary.
"Not a major amount, but it is an instant pain relief. It's more manageable. I can move my joints without them clicking too much or actually hurting. It just relaxes all your muscles and tendons. It's fantastic."
She would spend about $40 a week for one or two "tinnies" - a lot less than what she would have been spending on medication. Marijuana should not be illegal in New Zealand, she said.
Tauranga Senior Sergeant Glenn Saunders said he did not believe there were any incidents or arrests during the event. He could not confirm whether police attended the event.
Who uses cannabis?
Official statistics from Auckland University's Alcohol and Public Health Research Unit show half of New Zealanders aged 15-65 have tried cannabis, and one-in-six define
themselves as regular users.
- National Organisation for the Reform of Marijuana Laws