Most people said they had lied to impress someone.
George Orwell's 1984 and Leo Tolstoy's War and Peace are among the books people are most likely to have lied about reading, according to a poll.
Two out of three people admitted lying about reading a particular book to impress someone, the survey released to mark World Book Day found.
Orwell's classic topped the list, with four out of 10 respondents (42%) pretending to have read it.
And almost a third (31%) said they had lied about reading War and Peace.
1. 1984 - George Orwell (42%)
2. War and Peace - Leo Tolstoy (31%)
3. Ulysses - James Joyce (25%)
4. The Bible (24%)
5. Madame Bovary - Gustave Flaubert (16%)
6. A Brief History of Time - Stephen Hawking (15%)
7. Midnight's Children - Salman Rushdie (14%)
8. In Remembrance of Things Past - Marcel Proust (9%)
9. Dreams from My Father - Barack Obama (6%)
10. The Selfish Gene - Richard Dawkins (6%)
A total of 1,342 people took part in the online survey in January and February this year.
Visitors to the World Book Day website were given a list of 10 books and asked which they had lied about reading.
Others included The Bible (24%) and US President Barack Obama's memoir Dreams From My Father (6%).
Many also admit to wrongly claiming to have read the classics, including authors Jane Austen, the Bronte sisters, Charles Dickens, Fyodor Dostoyevsky and Herman Melville.
Most said they had lied to impress someone.
Francesca Simon, author of the Horrid Henry children's books recalled: "An Oxford don asked me if I knew Italo Calvino.
"I said yes, meaning I'd heard of him, but she meant, 'What had I read?' The conversation degenerated from there."
Asked which authors they really enjoyed reading, more than six out of 10 (61%) chose Harry Potter author JK Rowling, nearly a third (32%) ticked legal thriller writer John Grisham.
More than a fifth (22%) chose Shopaholic author Sophie Kinsella.
A further 41% of respondents confessed to turning to the back of a book to read the end before finishing the story and 48% admitted to buying a book for someone else and reading it first.