The 28-year-old dancer-actress was on the runway for designer James Ferreira's resort wear collection. She opened the show with a dance performance and later walked the ramp.
"I am not nervous while dancing. I can dance even waking up in the night. But modelling is different," she said.
The actress, who was seen in Subhash Ghai's 'Kisna' said she had no time to rehearse for the fashion show.
"We rehearsed for 15 minutes. Fashion is all about confidence and attitude. You watch models doing it and you do it giving your full," she said.
Isha will be performing at the National Centre for Performing Arts (NCPA) in Mumbai early next year where she will don a Ferreira outfit.
The actress, who became a household name with the dance show "Jhalak Dikhlaja" this year, is also awaiting her next Tamil movie "David" directed by Bejoy Nambiar scheduled to be released in February.