Atithi Tum Kab Jaoge? is the story of Puneet (Ajay Devgn) and Munmun (Konkona Sen), a happily married couple living in Mumbai whose lives take an interesting turn when a distant relative, Chachaji (Paresh Rawal) turns up unannounced at their doorstep from a far off village. The guest overstays his welcome so much so that the exasperated couple come up with various ploys to hasten his departure to hilarious results.