Tyler achieved international recognition as a result of her portrayal of Elf maiden Arwen Undómiel in the Lord of the Rings film trilogy. She has appeared in an eclectic range of films, including the 2004 comedy Jersey Girl, the indie film Lonesome Jim (2005), the drama Reign Over Me (2007) and big-budget studio films such as Armageddon (1998), The Strangers (2008) and The Incredible Hulk (2008).
Since 2003, Tyler has served as a United Nations Children's Fund (UNICEF) Goodwill Ambassador for the United States, and as a spokesperson for Givenchy's line of perfume and cosmetics.
In 2008, she starred in the horror-thriller The Strangers with Scott Speedman, a film about a young couple who are terrorized one night by three masked assailants in their remote country house. Although the film garnered a mixed reception among critics, it was a box office success. In an interview with Entertainment Weekly, she noted that The Strangers was the most challenging role of her career. "It was as far as I could push myself in every way: physically, emotionally, mentally."
She appeared in The Incredible Hulk (2008), in which she played Dr. Betty Ross, the love interest of the title character, played by Edward Norton. Tyler was attracted to the love story in the script, and was a fan of the television show. She said filming the part was "very physical, which was fun", and compared her performance to "a deer caught in the headlights". The Incredible Hulk was a box office success, earning over $262 million worldwide. The Washington Post, in review of the film, wrote: "Tyler gives Betty an appropriately angelic nimbus of ethereal gentleness as the one Beauty who can tame the Beast ... during their most pivotal encounters."
