Movie Extras is recruiting men over 18 with a Caribbean/Jamaican look for ITV's new three-part drama, Life Of Crime, which began filming in the city on Monday.
So far they have found around 30 suitable candidates but urgently need another 20.
Derek Quinn, of Movie Extras, said the people recruited are all from Dublin, as they may be expected to film on different dates.
He said the candidates applying so far have been excellent: "Some of the guys are fantastic. They are true blood Jamaicans with dreadlocks and the whole works."
Mr Quinn admitted finding 50 Caribbean or Jamaicans in Dublin was no easy task, but said it paled in comparison to some of the challenges Movie Extras have met.
"We were once asked to find a double for Eddie Izzard. The double had to be a leg amputee. They had to fit his measurements and look like him. I think it was for Treasure Island."
Life Of Crime stars Hayley Atwell (Nancy in The Sweeney) as a rookie policewoman who investigates the brutal murder of a 15- year-old girl in Brixton in London.
The first instalment is set against the backdrop of the 1981 Brixton riots.
Anyone interested in applying should contact Movie Extras.