Rachael Green, aged 30, from Wolverhampton was watching her favourite programme when a character in the episode noticed a mole change in shape, similar to one on her leg.
The mother-of-one had the mole for two-and-a-half years and only after realising the mole could be potentially fatal did she decide to get it checked out.
Doctors decided to biopsy the dark brown pea-sized melanoma on her lower leg and later confirmed she had a skin cancer.
Last month surgeons removed skin around the cancerous lump in the hope that the cells had been contained.
Now the postwoman has been advised to avoid the sun and will have to cover her skin fully to avoid any cell mutations in the future.
She said: "Holby City saved my life, if it hadn't have been for that episode on skin cancer I would never have had my mole checked out.
"I noticed it on my lower leg last year. I didn't remember having it before but noticed in pictures that it was changing in colour and size.
"It wasn't a regular shape, not a perfect circle and the colours weren't consistent, they were a mixture of light brown and dark brown.
"I kept saying I was going to get it checked a number of times but never did, if it hadn't have been for a character on Holby City who had a melanoma I don't know what would have happened to me."
By removing the cancerous skin doctors left Rachael with a large and graphic hole in her leg.
She added: "Since I had an operation to dig out a hole in my leg around where the mole was to make sure the cancer couldn't spread.
"At first the hole in my leg looked massive, I'm not squeamish but I couldn't look at it at, since then it's evened out a bit."
Doctors cannot fully account for what exactly caused Rachael's melanoma to develop, but one aggravating factor could have been that she had used sunbeds in the past.
The life-threatening scare has made her cautious about skin safety for herself and her two-year-old daughter, Lacy.
She added: "I deliver post, so it could affect me quite severely, even in the burning heat I'll need to wear trousers and cover-up all over, as well as always lugging sun cream.
"Now I'm even more protective of my daughter whenever she's in sun, I don't want this to happen to her and hope other people are more conscious of protecting their skin too."
Rachael is now raising money for the Skin Cancer Research Fund.
Visit www.justgiving.com/fundraising/Rachael-Green13 for more information.