Pestonjee is a story about two close friends, Phirojshah (Naseeruddin Shah) and Pestonjee (Anupam Kher), who do everything together and hope to marry on the same day.
Unfortunately, both fall for the same young lady, Jeroo (Shabana Azmi), and Pestonjee ends up marrying her. Phirojshah, captivated by Jeroo's beauty, decides not to marry and distances himself from the couple by taking a transfer.
Over the years, Phirojshah keeps in touch with the couple through mail. During a visit, he discovers that Pestonjee has a mistress unknown to Jeroo. This revelation puts their friendship to the test. Will Phirojshah's feelings for Jeroo come to light?