IT'S TOUGH LETTING GO: Angelina Jolie just got an A grade for being a great mother.

A video posted on Wednesday showed the 44-year-old Oscar winner turning up at Seoul's Yonsei University to drop off her son Maddox, 18, who is starting his biochemistry course.

They were previously seen scouting for universities in South Korea in November last year and Jolie made sure she was by his side again on his first day at Yonsei.

"I leave today; today is the day I drop him off," Jolie was heard talking to other students in the video.

But leaving him in Seoul while she returned to the United States was not easy for the mother.

It would have made for an easier transition for her if he had opted to study in, say, New York University, which he had reportedly considered.

"I'm trying not to cry," Jolie added, casting a look at Maddox, whom she adopted from an orphanage in Cambodia in 2002. She has five other children.