Dozens of teenagers kill themselves every year -- often around the time of an annual college entrance exam -- amid fears they didn't do well enough to enter the college of their dreams.
In one recent shocking case, a 16-year-old in the southwestern city of Mokpo doused himself with gasoline and set himself ablaze in the street.
He left a note saying he had done badly in tests and felt he had let his parents down.
The number of school-age suicides rose from 100 in 2003 to 202 in 2009, according to education ministry statistics.
Dozens more attempt to kill themselves but survive.
Another survey showed about 20 per cent of high and middle school students feel tempted to commit suicide, higher than 17.4 per cent among adults in one of the world's most suicide-prone countries.
South Korean teenagers have long studied late into the night to stay ahead in the rat race for admission to top universities seen as offering them a head start in life.
Education is highly prized in South Korea and plays a major role in determining job and marriage prospects.
Angela Kwon, a high school senior in Suwon just south of Seoul, attends school classes from 7.00 am to 4.00 pm.
Then she studies at a $1,400-a-month private cram school until 10.00 pm night -- before returning to her boarding school and swotting until 2 am in the library.
Even at weekends Kwon, like many of her age, spends most waking hours at the library and the cram school. She catches up on sleep when commuting.
Government data shows the average high school senior sleeps about five hours and studies more than 11 hours a day.
"Sleep has been so elusive for years...many of my friends say they are tired of feeling exhausted all the time," said Kwon, 18.
"I and my friends sneak out of school to watch a movie once every few months, but we feel extremely guilty."
Kim Hye-In, a high school senior in Suwon, said she and her friends wear rubber bands round their wrist and snap them periodically to keep themselves awake.
"Waking up in the morning after sleeping four hours is the hardest part of my day," said the 18-year-old, who usually studies until two in the morning to try to get into a music school of her choice.
"There's no freedom in my life now. We doze off during a class and often get beaten when caught by a teacher."
Today's children are "in a constant state of extreme exhaustion, sleep-deprivation and depression", said Park Jae-Won, head of Seoul's Visang Education Research Centre.
"Many parents push children to study at an increasingly earlier age regardless of their brain development...even causing depression or attention deficit disorders as a result," he said.
Bae Joo-Mi, a clinical psychologist at the Korea Youth Counseling Institute, said the number of calls for help has grown over the years.
"In the past, the competition kicked off in earnest in middle or high school, now it starts in elementary school," she said, adding it was inevitable for youngsters to feel more distressed and depressed.
"Callers in the past usually used to say, 'I feel so blue' or 'I feel so depressed'. But now they say 'I'm overwhelmed. I just want to die'," said Bae.
According to a recent survey by the National Youth Policy Institute, 71 per cent of South Korean teenagers said they were happy compared to 92 per cent in China and 75 per cent in Japan -- also well known for competitive education.
Education authorities have started, albeit in a limited way, to address the problem.
Seoul's education office said last November it would test all school students for depression and offer counselling for those deemed at risk.
The project suffered from a lack of resources and therapists. But education authorities also lamented that many parents refused to let their children get help for fear they may be stigmatised as mentally disturbed.
"Very few of the students deemed at risk actually end up getting counselling because their parents are unwilling," said an education ministry official who declined to be named.
There are some improvements. The official said 4,300 schools -- 38 per cent of the country's total -- now offer basic screening for depression and refer those at risk to professional counsellors, compared to 96 schools in 2007.
"Our kids are so crushed by the pressure to be excessively competitive and be successful at any costs...we can't afford to let the pressure keep crushing them like this," the official said.