"We decided to stop selling roses ... because some students received dozens and others received none," the vice-principal of Gärdes school in Stockholm, Lars Wikander, told AFP.
He said pupils who received no roses could feel excluded and suffer "from getting no attention at all throughout this special day."
"In the best of worlds, each student would receive a rose on Valentine's Day," Wikander said.
According to a study published on the website of the Swedish organization Friends, which combats bullying in schools, more than two-thirds of youngsters feel left out on Valentine's Day.
"Valentine's Day is a very positive day ... but there is also the flip side of the coin, which is that many youngsters feel bad," said Friends spokesman Magnus Jägerskog, adding that the day should be used to discuss friendship and how to treat loved ones.
The survey, which questioned 1,027 youths aged 14 to 24, was conducted by the Cint institute during the second week of February.