Bana is an advocate for the Mental Illness Fellowship, which works to increase the awareness of mental illness in Australia. In 2004, he appeared in several high profile advertisements for the fellowship. Bana is also active in campaigns with the Australian Childhood Foundation and the Bone Marrow Donor Institute. Since 1995, he has participated in the Motorcycle Riders Association Toy Run in Melbourne, which raises money and toys for needy children at Christmas.

In 2005, Bana narrated the documentary Terrors of Tasmania about the endangered Tasmanian Devil. The film followed the life of a female Tasmanian Devil called Manganinnie and discussed the incurable facial cancer which threatens the survival of the species. He has also worked with the Royal Society for the Prevention of Cruelty to Animals, donating money to animal shelters in Berlin while filming Troy in 2004.