Two of the teenagers were sentenced to 18 months in jail the third to 15 months, German news service Deutsche Welle reported Wednesday. Other students involved in the crimes received lesser sentences.
The students from the small northern German town of Hildesheim attracted international attention for the brutality of their crimes, which took place from November 2003 to January 2004.
During that period, the 17- and 18-year-old students kicked and beat one of their classmates and forced him to strip, eat chalk, chew cigarette butts and kiss their feet.
The abusers videotaped some of the abuse and posted the footage on the Internet.
A total of 11 students were tried for the crimes. Charges were dropped against two of them for lack of evidence and six received probation and the choice between community service or time in juvenile detention.