Attendees released purple balloons (for Caylee's favorite color) and butterflies in Florida near where her remains were found.
Several hundred people attended the memorial, and George and Cindy held hands and wore T-shirts that read, "You Will Always Remain In Our Hearts, Caylee Marie Anthony 2005-2008."
One month after Caylee's mother, Casey Anthony, was acquitted of murder, she remains in hiding, afraid for her safety.
Standing near the wooded area where the girl's remains were found in December 2008, George Anthony said: "We didn't know how we'd be perceived. It's just a great tribute to our Caylee. Other children have to come home, too. And that's what should be concentrated on now. We know where Caylee's at."
Splash News Online
Additional reporting by STEVE HELLING