Grizzly II: The Concert

The film's concert scenes were shot after an actual live performance by the band Nazareth had ended. The crowd was completely unaware that the following act was not a real rock band and that they were being recorded for a film. It was the largest public gathering in Hungary since the Hungarian Revolution of 1956.

The day after George Clooney, Laura Dern, and Charlie Sheen arrived in Hungary to start shooting their scenes for the film, its co-producer, Joe Proctor, told his fellow co-producer, Suzanne G. Nagy, that there was no more money to make it. He left 30 minutes later, abandoning 300 people that were already on the set to their fates. Nagy kept this to herself, desperately looking for any way to keep the film moving ahead. Luckily, a Japanese investor showed up and put up enough money to continue making the film. Nagy later went on to say that working with Clooney, Dern, and Sheen was terrific: all three were excited to be there and even pitched in to help by moving the film's sets and cameras and making themselves available whenever they were needed.

This film was mainly made in Budapest, Hungary in 1983. The Hungarian government then seized most of the film's equipment for non-payment of bills; as a result, post-production on it was never finished. Cannon Group, Inc. bought the film in 1987 and planned to both finish its post-production and release it, but the company began having financial troubles in 1988 and, as a result, it was mostly forgotten. Even the film's very existence was questioned until a work print of it illegally surfaced on the Internet in 2007.

Sometime in early 2020, it was announced that producer Suzanne G. Nagy had finally completed the film. A trailer for it was released online and it had been re-titled Grizzly II: Revenge.

The film was mentioned by the title "Grizzly II: The Concert" (a second working title for it) during the 46th Annual American Film Institute Life Achievement Award, which was awarded to George Clooney.