Bosses at Amici Ristorante, which is in Portstewart, near Coleraine, Northern Ireland, were furious with the no-shows as they meant other customers were unable to eat with them. The eatery took to Facebook to remind guests to cancel their bookings if unable to attend.
And the post was met with positive reaction, with guests calling the customer behaviour "disgusting".
As Belfast Live reports, the restaurant management shared online a list of the times and numbers of customers who had "no decency" to inform staff they would not be dining.
The post read: "We would like to apologise to all the customers who couldn’t get a reservation with us tonight…
"This is an insight to how our Saturday night service ended up, a total of 45 covers not showing in with no decency to cancel to free up a table for anyone else.
"We understand circumstances change but please make us aware.
"Just a reminder that we have a cancellation form on our website which sends us a direct email to cancel. Other ways to cancel are by email, phone or replying to your reservation reminder emails.
"We would like to take this opportunity to thank those customers who do take the time to cancel and turn up for their reservations."
The post, which has almost 500 likes and more than 250 comments, is filled with people who agree with Amici's frustration over the no-shows.
One comment read: "That's disgusting! Yes, we all have emergencies and unexpected things occur.
"But it is only manners and respect to phone and cancel. They'd expect it if the shoe was on the other foot."
Another said: "If I had a table booked with you I would be there! Our favourite. Poor form. Not hard to cancel."
The hospitality industry has been hugely affected by the pandemic.
There are reports restaurant and hotel closures are rising and will reach high levels next spring.
The amount of money lent by UK pub and bar owners to keep their own businesses afloat hit ￡138million last year, research reveals.