The woman, who wants to remain anonymous, said drug use at Bathgate Park had been an issue for more than a year.
"Day and night they are here [drug users]. It’s disgusting and we are sick of seeing it."
Users would "shoot up" on park benches and leave their needles on the ground — despite often being in sight of children playing nearby.
She was worried not only about the danger posed by the needles, but also about children being exposed to drug use.
Over the past year, she had complained to police multiple times, but nothing had been done.
Sick of the situation and police inaction, she last week uploaded photos of used needles and utensils she found near the playground, which was revamped by the Dunedin City Council last year.
Bathgate Park School principal Katrina Robertson was upset about the situation and said having needles lying around presented a significant risk to children.
"It is sad there is need for schools and parents to educate children around the dangers of picking up needles found in public places," Mrs Robertson said.
A police spokesman said rubbish in public areas was a matter for the council, which was the body responsible for the upkeep of Bathgate Park.
A council spokesman said it was not aware of the discovery of needles at the playground and encouraged anyone finding similar items to let it know.
Council contractors would check the park as soon as possible, the spokesman said.