In the duo's Jenny's Wedding, Heigl and Bledel play a lesbian couple who want to tie the knot in spite of Jenny (Heigl)'s conservative family's take on it.
In the debut snap, Jenny (Heigl) and Kitty (Bledel) smile and lean in for a kiss in what looks like a bridal shop.
The former Grey's Anatomy star has been hard at work trying to raise money for writer-director Mary Agnes Donoghue's film via an Indiegogo fundraising campaign, which she's hoping will lock in $150,000 by March 28 to complete post-production.
"Jenny's Wedding is a movie I'm so proud to be a part of," the 35-year-old actress, tweeted Wednesday. "Love the story and the characters. Hope you will too!"
"The producers are just as passionate about @jennys_wedding as I am, but need your help to make it happen," she later tweeted.
Fans who donate will receive signed screenplays, admission to advanced screenings with cast and filmmakers, retweets from Heigl and behind-the-scenes footage.
The film, which Donoghue is hoping to release by the end of 2014, is currently being edited.