A.J.'s Secret Lab is a hidden laboratory located in A.J.'s bedroom, which is accessible if a button is pushed.
This secret lab is hidden within the walls and under the floor boards of A.J.'s room. With the simple flick of a switch, A.J.'s room converts into this lab, and back again in order to prevent suspicion by either his mother or father.
The lab features a cloning tank with a clone of A.J. floating within a greenish liquid. There is also a large TV screen that A.J. uses to video chat with important people, giving them ideas on how to improve life on Earth. There also appears to be a Tesla ball as well as several hi-tech machinery in the lab. The floor is covered with white tiles and the walls appear to be metallic.
- In Who's Your Daddy?, when Timmy wished that A.J.'s dad was his dad, Timmy took A.J.'s place. When he heard his father come into the room, Timmy quickly flicked the switch to hide his lab and replace with a regular room.
- A.J. is also seen in his lab in Information Stupor Highway, where he was talking to a member of NASA, sharing his plan about placing some seeds in the back of a satellite so that when it orbits the Earth, it can plant seeds around the world. The NASA member thanks A.J. greatly for his idea, but A.J. cares mostly about the money.