Use indirect heat.When you’re working with thin fish filets, you don’t need high heat! A grill over medium heat will still get the beautiful grill marks without burning the filets.
Oil everything.To get the best grilled tilapia that doesn’t stick, you want to use plenty of oil! Cover the fish in oil, and be sure to oil the clean grill grates, too.
Use foil packets.If you want to be positive your fish won’t stick to the grill, use foil packets. Remember the nonstick side of foil is the dull side, not the shiny one! You’ll get that same grilled flavor without the broken filets.
Remove from the grill sooner than you think.One of the best tricks I’ve learned for grilled tilapia is to take it off the grill sooner than you’d imagine. Once the fish is brown, you can flip it. When it’s completely opaque, it’s done! You can always check the internal temperature with a meat thermometer, too. It should be at least 145°F/63°C.