The 31-year-old star shared a poster of the 2007 romantic drama on social media and asked her fans to celebrate the moment with her.
"And what an incredible journey it's been so far... #9yearsofSaawariya! Relive the #nostalgia with me! #SanjayLeelaBhansali #RanbirKapoor," she wrote.
The film also marked actor Ranbir Kapoor's debut in Bollywood.
Though her first film did not do well at the box office, Sonam was applauded for her work in movies like "Raanjhanaa", "Khoobsurat" and "Neerja".