Civil servant Amanda Warrington, from Yate near Bristol, spent 17 months and a staggering 1,000 hours completing the whopping 24,000–piece puzzle.
The 50-year-old then cut the two-stone puzzle into quarters and stuck it on the wall using extra-strong adhesive.
The mural — called Life: The Great Challenge — was the biggest in the world when Amanda’s sister bought it for her from a specialist internet supplier.
But it took her so long to complete, another puzzle fan beat her to the world record with a 32,000-piece puzzle.
Their masterpiece, called Double Retrospect, was started in February 2011 and is now the world’s largest.
Amanda, who works for the Department of Work and Pensions and lives alone, said: “I didn’t really know what to do with it when I first started, but it was so pretty I thought it would look good on my wall.”
The brightly coloured brain teaser, which sizes up at 14ft x 5ftm contains a montage of animals, fish, boats, hot air balloons, an underwater city and planets.
She admitted: “I love a challenge. I must have done around 50 puzzles.
“They do take a while, but when you’re finished, you get such a great sense of satisfaction.”