- For the Washroom on the second floor, see Washroom (2F).
After Luigi collected five Boos in Luigi's Mansion, Professor E. Gadd mentions Luigi that he should go to the Washroom (Japanese: トイレ Washroom), which had just been unlocked. When Luigi goes inside, he notices Toad alone crying and cowering in a corner. When the plumber speaks to Toad, he mentions that he dropped something important inside the toilet. By reassuring Toad, the lights in the Washroom turn on. Afterward, in true plumber fashion, Luigi opened the toilet for inspection. Instantly, the key to the Fortune-Teller's Room popped out.
If Luigi tries to go in the Washroom before he got five Boos, he would find the door locked. A text box would then come up, reading, "Erm, OCCUPIED!" which can simply be Toad's attempt toward of whoever was trying to get in for fear of the ghosts.
The Washroom, being smaller than the Bathroom, is quite cramped. Starting on the west side, there is toilet with an antique-style hanging tank, a mirror overlooking a sink, a radiator, and a medicine cabinet. The sink will often contain a 10 HP or 20 HP restoring heart for Luigi.
Ghosts in The Washroom (1F) during the blackout
- One Red Grabbing Ghost (20 HP)