The Croatian actor became involved with local theater at age 9 and tackled Shakespearean stage roles before segueing to film and TV parts in his homeland. With war approaching, Visnjic became a paratrooper and served in the Yugoslav army before enlisting in the Croatian army at age 18. When his service was over, Visnjic attended the Academy of Dramatic Arts in Zagreb and, at age 21, landed the lead in Hamlet at the National Theatre, a part he held on-and-off for seven years. After a talent agent spotted him in Welcome to Sarajevo, he went to Hollywood and took notable English-speaking roles in the films The Peacemaker and Practical Magic. This exposure led to his being cast as the brooding Dr. Luka Kovac beginning in the sixth season of the popular medical drama ER. Married to a Croatian sculptor, Visnjic maintains strong ties to his native country and continues to act in Croatian—as well as Hollywood—projects.