The world's wackiest scientist has done it again!
Wayne Szalinzki, a wacky, absent-minded inventor, is back again but only this time he decides to use his infamous shrink machine just one more time. His wife Diane asks him to get rid of the "Tiki Man" a large tiki sculpture. Wayne refuses to get rid of it so he decides to restart the shrink ray and reduces the Tiki Man to pocket-size. However, after Wayne shrinks the Tiki Man the machine is accidentally activated and Wayne ends up shrinking himself and his brother Gordon. Meanwhile, when Gordon's wife Patty and Diane were going on a vacation they went back to the house when Patty suddenly realizes she forgot Mitch's medicine for his potassium deficiency. When they were about to leave, they decide to sneak into the attic and surprise the men, but the shrink ray is activated once again, and the ladies are shrunk as well. So the team must be very brave of disgusting household insects the size of dinosaurs and more in their biggest adventure to get their children's attention.
Once more--as if shrinking his children and the neighbours' kids in Honey, I Shrunk the Kids (1989), and zapping his boy in Honey, I Blew Up the Kid (1992) weren't enough--the well-meaning inventor, Wayne Szalinski, gets neck-deep into trouble, when his particle-altering machine gets into action. This time, the infamous device shrinks not only Wayne and his brother, Gordon but also Mrs Szalinski and her sister-in-law, Patti. At last, the kids have the house to themselves; however, the minuscule parents hear and see everything, even though they have a hard time navigating in the vast and perilous household environment while doing battle with gargantuan six-legged creatures. Will Wayne never learn?