De Niro is opening the Sarajevo Film Festival on Friday with a screening of his 1976 classic Taxi Driver, digitally restored for its 40th anniversary.
He is also due to be presented with a lifetime achievement award.
Sarajevo's film festival was founded in 1995 during the Bosnian war, after nearly four years under siege.
About 300 taxi drivers have put up posters in De Niro's honour, Reuters reported.
"Many of our colleagues became taxi drivers after being retired from the Bosnian army and in a sign of gratitude and compassion with the main character we have decided to stage him a warm welcome in this way," Hasib Losic of the Sarajevo Taxi Association told the agency.
Taxi Driver depicts the life of an isolated, angry army veteran turned taxi driver on the streets of New York.
Taxi drivers in the Bosnian capital Sarajevo have been putting posters of Robert De Niro on their vehicles in tribute to the actor ahead of a visit.