The annual Omahu Valley Bullride at the Sports Arena in Paeroa concerns animal welfare organisation, SAFE.
SAFE is calling on Hauraki, Waikato and Coromandel residents and sponsors to boycott this Saturday's bull ride.
SAFE Campaigns Officer Marianne Macdonald says rodeo is a form of bullying.
"Rodeo is essentially bullying animals for entertainment. Normally docile bulls are induced into aggressive behaviour by painful or irritating means such as flank straps, electric prods, tail twisting, and painful spurs - leading to aggravated and enraged animals who will perform.
At Omahu, vulnerable young calves are put through the stress of being ridden by competitors.
"We strongly urge local residents not to condone this cruelty by attending the rodeo," she said.
Ms Macdonald said common injuries include torn ligaments, broken bones and severe bruising.
A bull and a horse both died during events in the 2015-16 New Zealand rodeo season, with two bulls killed in the previous season, she said.
The Omahu rodeo is the second of the New Zealand series of the season throughout the country.
Richard Harden, treasurer of the Bull Riding Puriri says rodeos are now better regulated.
"We have a Code of Welfare that we are following, so it shows we are doing things right.
No calves are injured during the event," he said.
He says calves must weight a minimum of 150kgs to be selected for this rodeo.
"Hopping on their back, there are kids (between 12 and 16) who are lucky to be over 35kgs," he said.
The Code of Welfare for rodeos was established by the National Animal Welfare Advisory Committee (NAWAC) in March this year, setting up guidelines for best practices and minimum standards for all rodeo animals, including those used in training schools.
This Saturday's four-hour show will have 80 rides with 20 top competitors, open bull riders as well as 16 second division riders, seven juniors and four calf riders.
The top competitors will ride circuit bulls, part of the whole New Zealand rodeo season lasting around five or six months.
"Those bulls are used to it and they love it. People who follow the shows get used to bulls' names and encourage them. Each bull has its own personality," he said.
Mr Harden said riders take care of their animals.
"Every rodeo rider has got animals at home, whether it is farm animals or pets. It is in their best interest to look after them.
"I have never seen any stress or injuries on animals during the rodeo but the stress I have seen is coming from mothers who are watching their children riding and are worried.
"SAFE have the right to voice their opinion but at the end of the day, if they do not like this type of event, they do not have to attend or protest over it," he said.
More than 62,000 New Zealanders signed the national SAFE petition to ban rodeo delivered to Parliament in March this year.
"It is time to focus on teaching values of respect and compassion to impressionable children, making clear to them that tormenting animals is wrong," Ms Macdonald says.
"Towns and cities across New Zealand have so much to offer both locals and tourists, without causing harm to animals.
"We encourage people to embrace alternative forms of entertainment."
More information:
Gates open 10am, event starts at 11am this Saturday (November 26) at Omahu Valley Road (between Thames/Paeroa).
• $2000 open - 2x long and short round. $600 2nd division - 1x long and short round.
• NZRCA member calf ride. NZRCA member steer ride.
• Limited entry jackpot Open Barrel race at lunch.