Csokas is best known for his stage performances that include playing Septimus in Arcadia and Brutus in Julius Ceasar; helmed by the Auckland Theatre Company. His noteworthy stage performances include Peribanez Y El Comendador De Ocana (2006) and Who`s Afraid of Virginia Woolf (2007). His portrayal of Ted Healey in the TV movie, The Three Stooges, won him an Emmy nomination. His best movie roles include the Lord of The Rings Series in which he plays Celeborn in two of the three franchises, The Fellowship of The Ring (2001) and Return of the King (2003).
Other notable performances include movies like xXx (2002), Star Wars Episode II (2002), Alice in Wonderland (2010), Abraham Lincoln: Vampire Hunter (2012), The Amazing Spider-Man 2 (2013), Sin City: A Dame to Kill For (2014), The Equalizer
(2014), Loving (2016), Burn Your Maps (2016) and True Crimes (2016). Csokas has also starred in TV shows like Rogue (2013- ), Klondike (2014) and Into the Badlands (2015- ). Csokas stars alongside Emilia Clarke and Caterina Murino in Eric D. Howell`s supernatural mystery thriller Voice from the Stone (2017). The movie is based on a novel of the same name by Silvio Raffo.