The joke's on absent-minded scientist Wayne Szalinski when his troublesome invention shrinks him, his brother and their wives so effectively that their children think they've completely disappeared. Of course, this gives the kids free rein to do anything they want, unaware that their parents are watching every move.
| Actor | Role |
|---|---|
 Rick MoranisWayne Szalinski | Wayne Szalinski |
 Bug HallAdam Szalinski | Adam Szalinski |
 Allison MackJenny | Jenny |
 Robin BartlettPatti Szalinski | Patti Szalinski |
 Stuart PankinGordon Szalinski | Gordon Szalinski |
 Eve GordonDiane Szalinski | Diane Szalinski |
 Mila KunisJill | Jill |
 Theodore BordersTrey | Trey |
 Erica LuttrellJody | Jody |
 Carlease BurkeMarcia | Marcia |
 Jake RichardsonMitch Szalinski | Mitch Szalinski |
| JJoJo AdamsRicky | Ricky |
| BBryson AustVincent | Vincent |
| LLaura DunnTrina | Trina |
 Robert HarveyPostman | Postman |
| AAshleigh SterlingCorky | Corky |
 Lisa WilhoitHolly | Holly |
 George CarlinMan (uncredited) | Man (uncredited) |
| DDogTrouser the Dog (uncredited) | Trouser the Dog (uncredited) |
| HHannah WatermanTrina (uncredited) | Trina (uncredited) |