ET caught up with the 28-year-old actress at the premiere of her new movie, Flatliners, in Los Angeles on Wednesday, where she revealed the reason behind her chic beauty makeover.
Dobrev told ET's Ashley Crossan that she chopped her locks "about two hours" before our red carpet interview.
"It's for a new movie that I'm doing," she explained. "It's a movie called Lucky Day and I play a Parisian woman who's an artist. They wanted me to cut my hair and... I don't know. I couldn't have been more excited to do it."
While Dobrev couldn't reveal much about Lucky Day just yet, she had nothing but amazing things to say about Flatliners, and what it was like working with Michael Douglas, who is one of the film's producers. In the Niels Arden Oplov-helmed project, Dobrev plays Marlo, an overachiever who, along with other medical students, conducts dangerous, near-death experiments.
Dobrev told ET that she and her co-stars, which include Ellen Page, Diego Luna and Kiersey Clemons, actually went through a medical boot camp to prepare for their roles.
"We did two, maybe three weeks of medical training," Dobrev revealed. "We learned how to use a defibrillator and all of the tools that you would need to have to resuscitate a human in a dire situation."
"We were playing doctors, so they wanted us to look like we knew what we were doing while we were actually doing it," she continued. "I don't want to say I could save a life, but I could definitely keep someone alive long enough until the real paramedics came."
As for working with Douglas, who also produced the original 1990 film of the same name, Dobrev said her experience was "absolutely incredible."
"For all of us, we all saw [the original] and decided there's nothing that you could argue, if he's making his own movie over again," she said. "He's a legend and an icon. I look up to Michael in so many ways. And it was so great to have him, he was so present. He was there on set every day. I worship the ground that he walks on -- but don't tell him!"
And it sounds like the feeling is mutual. Watch the video below to hear Douglas' interview with ET!