List of Luigi sightings in New Super Luigi U

In every course of New Super Luigi U is a picture of Luigi hidden, whether it be a sprite, a image in a wall, or otherwise.

3-4 The Great Geysers

 * Behind the course's starting point is a series of large blocks with lines made to resemble Luigi's head.

5-2 Dancing Blocks, Poison Swamp

 * A Luigi sprite can be seen clinging to the top of the secret flagpole.

5-Ghost House Boo's Favorite Haunt

 * There is a portrait of Luigi to the right of the door leading to the secret exit.

6-5 Rising Piranhas

 * There is a large Luigi-shaped hole in the rock wall just before the Super Piranha Plant next to the secret exit in the ceiling.

7-Ghost House Vanishing Ghost House

 * If the player takes the secret exit route, he/she will see a picture of King Boo and Luigi, which references their artwork from Luigi's Mansion: Dark Moon.

7-5 Flame Chomp Ferris Wheel

 * A cloud resembling Luigi can be seen in the background.

8-1 Magma Moat

 * There is a statue of Luigi taking off his hat at the secret flagpole.

9-6 Fire Bar Sprint

 * Break the last set of blocks near the flag pole to find a crouching 8-bit Luigi.