Fantasmic! is performed on select nights only. So, make sure you plan ahead. This is a park favorite, so it does fill up. My suggestion is to get in line for the show at least an hour before the show. Or better yet, if you plan to have dinner in the park, make a reservation for the Fantasmic! Dining Package at The Hollywood Brown Derby, Hollywood & Vine or Mama Melrose’s Ristorante Italiano (my pick is Mama Melrose) and get reserved seating for the show. Seats are not assigned for this. So, you still need to show up a half hour beforehand. But, you will be guaranteed a seat and won’t have to wait in line.
Other tips: If you aren’t interested in the dining package, try and go on a night when the show will have two performances. The second show usually isn’t as crowded. Don’t sit in the first few rows unless you don’t mind getting a little wet. Some parts of the show are very dark and get a bit loud. So be prepared if you have little ones or are sensitive. There are concession stands and restrooms at the back of the amphitheater.