The then 42-year-old was lying in a hospital bed after having lost sensation in the left side of her body.
She thought it a really bad inner-ear infection or that something was wrong with her neck.
But what began as general fatigue and vertigo actually turned out to be symptoms of MS.
“The doctors were saying it could be the result of a stroke or MS,” Ms Kingsford Smith said.
“The minute I heard MS, I said: ‘Not me, I don’t want it.’ I didn’t know what MS was but I knew I didn’t want it.”
Multiple Sclerosis sees the immune system eat away at the nerve’s protective covering and affects three times as many women as men.
“Doctors think I probably had the disease anywhere from two to five years before being diagnosed,” Ms Kingsford Smith told news.com.au
“I was really fatigued, had been suffering vertigo, and found myself clinging to walls and having trouble with spatial awareness for a while.
“I assumed it was because I was a busy career and party girl, so thought it was normal.”
And while the news was devastating, the 47-year-old is getting on with life.