The couple were served steak with maggots and Stella Kim said she still feels ill recalling the incident.
The Ranch Hotel, on Sydney's north shore, is now trying to defend its food.
While the pub insists it takes food safety 'very seriously' it has admitted that the crawling larvae found its way onto the meal.
Ms Kim visited the hotel, located in North Ryde, last week with her partner Sushil Lamichhane to celebrate being together for 1000 days.
The couple both ordered steaks but when they arrived, the unwanted garnish was immediately apparent on one of the dishes.
'[I] just couldn't believe if this was real. It was horrible, unbelievable,' Ms Kim told News Corp.
'Maggots were crawling over and there was a lot of them. It was like a rotten carcass,' she continued.
A video posted to Facebook showed the small, white creatures slithering across the meat.
'For a few days we just lost our appetite. It is very hard for me to even [talk about it] now,' Ms Kim further added.
The Ranch Hotel is owned by Australian Leisure and Hospitality (ALH) Group, a joint venture between the Mathieson family and retailer Woolworths.
On the pub's website, the management said they served 262 steaks that day but just one was returned due to its unwanted ingredient.
'Our investigation concluded the incident was due to blowfly larva laid after the meal was cooked, as it is not possible for larva to survive the cooking process. All our kitchen staff are experienced and accredited in food safety and The Ranch stands by its food safety record and processes.'
The statement said the pub had reported itself to the local council and had apologised to Ms Kim.