Stephen Fry: Out There on ABC1 with Stephen Fry and Neil Patrick Harris. Image supplied by ABC TV publicity.

Stephen Fry and How I Met Your Mother star Neil Patrick Harris.

ABC1, Monday, 8.30pm

This two-part documentary, written and presented by Stephen Fry, sees the British polymath coming over a bit Louis Theroux as he travels the world, to explore ''what it means to be gay'' and attitudes to homosexuality.

Over more than two years, Fry visited Uganda, Russia, Brazil, India and the US, meeting both perpetrators and victims of homophobia. Tonight, he's in Uganda, with the aim of confronting ''notorious homophobes'', in order, he tells us, to ''challenge their prejudices and find out where the hatred comes from''.

But first up, Fry attends a civil marriage in London (where he even sheds a tear during the ceremony) before heading to the Berkshire mansion of Sir Elton John and his partner, David Furnish. John coming out in the 1970s, says Fry, was a ''game-changing moment'' for him as a teenager.

But for all the progress in Britain (where homosexuality was legalised in 1967), there are still 84 countries where homosexuality is a crime. At the time of filming, the Ugandan government was proposing a new law that would put gay people to death - it has since been passed, but the death penalty was dropped; now the ''anti-homosexuality bill'' allows for repeat offenders to be jailed for life, and also makes not reporting gay people a crime punishable by law - and Fry meets with two campaigners of the bill. First he goes head to head with Ugandan pastor Solomon Male, but only ends up in a shouting match. Then he meets with government minister Simon Lokodo, and, again, Fry just ends up frustrated. His heated exchanges with such bigots are understandable, but the gravity of the situation feels a touch undermined by Fry's exasperation and mocking. This tone does work to good effect, though, when he meets, in Los Angeles, a practitioner of ''Reparative Therapy'', who claims to ''cure'' gay people, and disarmingly tells the practitioner he could pass for a gay man.

Fry is at his best, though, and the program at its most moving, when he meets victims of homophobia - Stosh, a Ugandan lesbian who was a victim of ''corrective rape'' at 14, or a particularly affecting moment when he meets Farshad, who is seeking asylum in the UK from his homeland Iran, where homosexuals can be hanged (Fry says he wanted to go to Iran, but the BBC deemed it unsafe). In part two, he travels to Russia, India and Brazil, but this first episode is a tad celebrity-heavy, including openly gay actor Neil Patrick Harris, best known for playing, as Fry says, one of the straightest characters on television in How I Met Your Mother. Patrick Harris says when he came out he was ''anticipating outrage and I got indifference'' - a sign, Fry believes, that progress has been made, at least in the West. It also allows him one of the best lines in the program: ''Hollywood,'' he says, ''is the thermometer that is thrust up the anus of the world's sensibility.''