In the remote Irish village of Tullymore, someone has struck it rich, winning several million in the National Lottery. Since it is a close-knit, traditional Irish village, everyone knows everyone else's business, yet it remains mystery who might have won. Clever Jackie O'Shea (Ian Bannen) tries to find the winner through a process of deduction, analyzing everyone's behavior and hosting a fancy chicken dinner for potential winners (so as to curry favor and perhaps receive a bit of the winnings himself). Finally, it becomes clear that only Ned Devine, an elderly retiree who lives alone, could have won the prize. Jackie and his friend Michael O'Sullivan (David Kelly) call on Ned, only to find the poor man stone dead, clutching the Lottery ticket in his hand, and with a smile on his lips. The shock of winning killed him!
The scheming Jackie tries to figure out a way to cash the ticket, but has a dream in which Ned Devine prompts him to share the money with the impoverished village. So he concocts a crazy scheme: his friend Michael will pose as Ned when a representative from the Lottery commission (Adrian Robinson) comes to verify the winner. In a series of humorous events, the entire village (save one) convince the Lotto observer that Michael is legitimately Ned Devine, and even devise an offshore banking scheme to cash the check.
The town begins celebrating, when the old "witch" Lizzie Quinn (Eileen Dromey) threatens to turn them in for a fraud reward. She even attempts to reach the only working phone in the area (a telephone box along a winding coastal road). Her motorized wheelchair runs out of juice, so she staggers to the phone booth. As she tries to complete the call to betray them all, the phone box is struck by the Parish Priest in his van, and Quinn plunges to her death.
Thus, everyone in Tullymore becomes a millionaire, and all the loose ends are tied-up.