Passing sentence today, Judge Gordana Bozilovic-Petrovic explained that the offences constituted war crimes against a civilian population.
"By committing such acts against defenceless civilians, by showing off their power and not showing remorse, the defendants did not give the court the choice to pass lower sentences," he said.
Slobodan Medic, the commander of the paramilitary unit, and his main accomplice Branislav Medic both received 20-year sentences from the Serbian war crimes court.
Pera Petrasevic, the only defendant to plead guilty to the charges, was jailed for 13 years, and Aleksandar Medic was told to spend the next five years behind bars.
A fifth defendant, Aleksandar Vukov, was acquitted.
The 18-month trial, which heard testimonies from 21 witnesses, was prompted when video evidence of the Srebrenica massacre was shown at the war crimes trial of late Yugoslav president Slobodan Milosevic in 2005.
The footage shocked many Serbians, who up until that point did not believe the massacre actually occurred.
It showed the four men found guilty today taunting their victims shortly before shooting them in the back of the head in woods near Srebrenica.
Click here to run an energy price comparison, and see if you could be paying less for your gas and electricity.