Five-year-old Monty, from Bristol, was placed in water soluble anaesthetic during the procedure on his left eye, which cost its owners 200 pounds.
The cancerous cells had spread throughout its back, rendering the surgery necessary.
Although the goldfish lost an eye to the surgery, it is recovering well, 'metro.Co.Uk' reported.
"He was a brilliant patient and the surgery went very smoothly from start to finish," said Sonya Miles, exotics veterinary surgeon at Highcroft Veterinary Group, who assisted Bristol Zoo vet, Michelle Barrows in the surgery.
"We don't perform surgery on goldfish very often but we are seeing a definite increase in veterinary treatment in fish generally.
"Monty is doing exceptionally well at home and is acting as if nothing has even happened," Miles said.
