From 1995 until 1997 he was a member of the Budapest Chamber Theatre, between 1997 and 2008 a member of the Comedy Theatre of Budapest. He won widespread admiration for his first role playing Othello at the age of 23 in 1995. For the Budapest Chamber Theatre he has also starred as Horst in Martin Sherman’s Bent (1996), Treplyov in Anton Chekhov’s The Seagull (1997), Stanley Kowalski in Tennessee Williams’s A Streetcar Named Desire in 1999 (a role he had previously played for the National Theatre of Győr in 1997), Romeo in Romeo and Juliet (1998), and James Tyrone Jr in A Moon for the Misbegotten by Eugene O’Neill (2003).

Kamarás has shot an experimental film on his mobile phone, Sigh, which was inspired by the Yukio Mishima drama Aoi no Ue and which screened at the Hungarian Film Festival in 2005 and the Moziünnep film festival in 2006. He undertook a course in directing at UCLA in 2009 and in the same year directed a production of Tchaikovsky’s opera Eugene Onegin at Keszthely Castle, Hungary.

In addition to Silent Witness – in which his character, detective Tibor Orban, helped to uncover a baby-farming racket in Budapest while trying to track down series regular, forensic pathologist Dr Harry Cunningham – Kamarás has played Pipin, the son of Charlemagne, in the miniseries Charlemagne (1993); Louis II, King of Hungary, in the costume drama Mohacs (1995); Ivan, a man who becomes obsessed on his wedding day with his newly met twin sister in Alice and the Seven Wolves (2009); and the machiavellian nightclub owner and antihero Evil in the 10-part drama First Generation (2001). He was also the creative force behind Mobile Poem, a series of poetry readings done by notable Hungarian actors and filmed on mobile phone, which screened on the Hungarian TV channel MTV1 in 2009. In January 2011, he played a Hungarian detective, Tibor Orban, in Bloodlines, the fourth episode in the 14th series of the BBC crime drama Silent Witness. In 2014 he played the role of Rasputin in the two-part History Channel miniseries Houdini.

Aside from his role as Agent Steel in Hellboy II: The Golden Army, Kamarás has had an extensive career in Hungarian cinema. Notable roles have included the hit bedroom farce Out of Order (1997), in which he played a jealous boxer in pursuit of his errant girlfriend and her politician lover, the thriller Európa expressz (1999), in which he played Jimmy, a man who becomes caught up in events when the train he is in is hijacked by a Russian mafia boss, and more recently the cult comedy GlassTiger 3 (2010), in which he played Ferenc Csopkai, a rich lawyer who pursues the bumbling heroes after they steal his car and with it a huge sum in cash. In 2013 Kamarás starred in the film Outpost: Rise of the Spetsnaz.